FERGUSON, Mo. -- President Obama on Tuesday offered his “deepest condolences” to the family and community of Michael Brown, an unarmed black Missouri teenager who was shot to death by police Saturday.

In a statement, Obama said that the 18-year-old’s death has “prompted strong passions” but urged people to remember Brown, through “reflection and understanding.”

“I know the events of the past few days have prompted strong passions, but as details unfold, I urge everyone in Ferguson, Missouri, and across the country, to remember this young man through reflection and understanding,” Obama said. “We should comfort each other and talk with one another in a way that heals, not in a way that wounds. Along with our prayers, that’s what Michael and his family, and our broader American community, deserve.”

Attorney General Eric Holder has said the Department of Justice is investigating the shooting. Obama said the administration will “continue to direct resources to the case as needed.”

Obama’s comments came after protests over Brown’s death turned contentious late Monday and early Tuesday, leading to an hours-long standoff in Ferguson between several dozen local residents and dozens of officers in full riot gear just blocks from where he was killed.

Law enforcement officers lobbed tear gas canisters and shot rubber bullets at enraged protesters who refused to clear the street.

“I’ve never in my life seen anything like this,” said Eric Crawford, 25, who was caught by a volley of tear gas. “You’ve got people who are standing in their front yards getting shot with tear gas - in their front yards, at their own houses.”

Some residents stood down police dogs, armored vehicles and pointed guns while chanting, “we’re unarmed don’t shoot.”

Not long after Obama’s statement, the Federal Aviation Administration said that it had banned flights from operating below 3,000 feet over Ferguson, at the request of police. The agency’s notice said it was issued “to provide a safe environment for law enforcement activities.”

The temporary restrictions were implemented at the request of the St. Louis County, Mo., Police Department. Police asked for the restrictions on Monday because their helicopter was shot at “multiple times on Sunday night,” Brian Schellman, a spokesman for the police, said in an e-mail to The Post.

Also on Tuesday, several hundred residents descended on the St. Louis County prosecutor’s office. Standing on the steps of the county building, the protesters chanted “no justice, no peace,” before taking to the streets.

“Hands up, don’t shoot,” they yelled as they made their way through downtown Clayton.

Later, they came face to face with officers guarding the prosecutors’ office, chanting, “Who do you serve? Who do you protect?”

The consensus -- among many residents, community leaders, and journalists both visiting and local -- is that the unrest that has gripped this town for fours days has only just begun.

The FBI on Monday launched a civil rights investigation into the fatal shooting that has pushed the question of race and the use of lethal force again to the forefront of national discussion.

The details surrounding Brown’s death remain unclear. But the case is recalling the racial animosity surrounding the fatal shooting of 17-year-old Trayvon Martin in Florida in 2012 and other recent altercations between African Americans and police. The Martin case drew in President Obama, who called for calm amid similar anger and noted that, if he had a son, he would “have looked like Trayvon.”

Obama did not comment on the Brown case Monday during a public appearance in Martha’s Vineyard, Mass., where he is on vacation.

Brown’s family moved to hire lawyer Benjamin Crump, who represented Martin’s family after the teenager, also unarmed at the time of his death, was shot by a neighborhood watch volunteer. Appearing here, Crump called Brown’s shooting “another senseless death of another person of color.”

Police had been expected to release on Tuesday the name of the officer who shot and killed Brown, an 18-year-old who would have begun college on Monday. But Timothy Zoll, a spokesman for the Ferguson Police Department, told The Washington Post that the name won’t be released because of threats made against Ferguson police officers on social media sites.

The officer involved in the incident has been placed on paid administrative leave. There is no timetable for when police could release the officer’s name, Zoll said.

A group claiming to be associated with the hacking collective Anonymous said Tuesday that it knew the name of the officer and was working to be sure it had the right person before identifying him. This group also said it had launched cyberattacks on the city of Ferguson’s Web sites following the police response to looting on Sunday night.

Ferguson’s site and e-mail systems were both hit with cyberattacks that appeared to be continuing into Monday evening, Pam Hylton, the assistant city manager, told The Post.

Civil rights activist Al Sharpton was expected to arrive in Ferguson on Tuesday. “It is a broader problem that we see in many circles, the feeling that black young men in particular are expendable,” Sharpton, an MSNBC host, said Monday in an interview with The Post. “There is a racial aspect in this as well as a class aspect in this.”

Residents describe the current outrage echoing through the city as the product of years of tense relations between Ferguson’s majority-white police department and its majority-black population.

“It’s not right,” said Craig Ruffin, 29, a protester who faced tear gas on Monday night. “I’m a single parent of a 7-year-old daughter. That could have been her dead in the street.”

Details remain scarce as to what exactly led to Brown’s shooting. Police say he started a scuffle with an officer and reached for the officer’s gun.

Jon Belmar, chief of the St. Louis County police, said Sunday that a Ferguson police officer “had an encounter” with Brown and another person Saturday. At some point, the officer reportedly was pushed back into his car and “physically assaulted,” the chief said.

There was a struggle over the officer’s weapon, which was fired once in the car, Belmar said. Following that, the officer got out of the car and fired at the teenager multiple times. Brown was killed about 35 feet from the officer’s car, Belmar said.

Residents in the neighborhood of the shooting have circulated an account of the incident in which the officer initiated a confrontation, drove his cruiser in reverse at Brown as he walked down the street and then shot him several times as he attempted to surrender.

A man who says he was with Brown during the incident told MSNBC in an interview posted online Tuesday that they were walking together when a police officer in a cruiser told them to “get the f---- on the sidewalk.” Dorian Johnson, 22, said the two continued to walk, and the encounter escalated into a physical confrontation, with the officer nearly hitting them with his vehicle, MSNBC reported.

Johnson told MSNBC that the officer fired at Brown several times, even though Brown tried to run away and yelled “I don’t have a gun, stop shooting!”

Most infuriating for many residents is the rumor -- unconfirmed by police but spreading rapidly on the streets of Missouri -- that Brown was shot in the head as he lay dying on the pavement.

“I just put myself in his shoes,” said Duane Finnie, 36, a childhood friend of Brown’s father and friend of the family. “Your last seconds of life and you’re getting shot down - executed - by someone who is supposed to protect you.”

It was those sentiments that echoed at a crowded meeting of the local NAACP early Monday evening, at which community leaders urged responsible protest.

But it was just minutes after the hundreds had begun departing from the meeting that demonstrations near the site of Brown’s death turned tense.

In an attempt to disperse the crowd Monday night, officers made their way down West Florissant, a main street in Ferguson. When some residents, chanting “Don’t shoot, my hands are up,” refused to leave, officers began using tear gas.

Johnson and other residents have said that the encounter between Brown and the officer began when the officer ordered Brown not to walk in the street. That hints at an issue facing black residents of Ferguson and other cities.

While black residents accounted for 67 percent of Ferguson’s population, black drivers accounted for more than 86 percent of the traffic stops made last year by the Ferguson Police Department, according to a report produced by the office of Missouri Attorney General Chris Koster.

And the majority of the traffic stops (92 percent) that ended with arrests involved black drivers.

Statewide, black drivers “were 66 percent more likely than white drivers to be stopped” last year, Koster said in a statement in May.

The numbers were not much different for the St. Louis County Police Department, which is investigating the shooting at the request of the Ferguson police. Last year, 32 percent of the traffic stops made by the county police involved black drivers. Nearly half of the stops ending in arrests (47.9 percent) involved black drivers, while 50 percent involved white drivers, despite white residents making up 70 percent of the county’s population.

A former lieutenant with the county police was fired last year after an investigation found that the lieutenant, who was accused of ordering officers to target black people around stores in the county, had made “inappropriate racial references.”

In the wake of the allegations against the lieutenant, St. Louis County Executive Charlie Dooley asked the county police board to produce documents and statistics regarding racial profiling.

The county police are participating in a study of the department’s protocols conducted by researchers from the University of California at Los Angeles. “We want to make sure we’re not stopping people based solely on their race,” Belmar told the St. Louis Post-Dispatch when researchers visited the department in May.

Berman reported from Washington. Zezima reported from Edgartown, Mass.