Several hundred people gathered outside the White House in two successive tense and confrontational demonstrations occurring hours apart on Friday, both of them protesting the death of George Floyd, who died after a Minneapolis police officer pressed his knee into Floyd’s neck.

The demonstration had showed no signs of slowing as crowds continued to face off with police after 3 a.m. Saturday. Officers used what appeared to be gasses and sprays to disperse crowds, and protesters were throwing water bottles at a line of law enforcement amid the scene that remained tense more than 10 hours after the initial demonstration started.

By about 3:30 a.m. police had issued two warnings to the crowd before a line of officers with shields were seen advancing on the group that was chanting “black lives matter.” People scattered after the deployment of a spray as officers shouted “the park is closed!” U.S. Park Police, uniformed Secret Service officers and D.C. police all appeared to be at the scene pushing protesters through Lafayette Square Park outside of the White House before the crowd finally broke up.

At one point, protesters chased a Fox News reporter out of the scene, screaming expletives at him, though it was unclear what preceded the incident.

Shortly after 2 a.m. the tension grew after a someone appeared to have grabbed a shield from an officer and ran into Lafayette park. Many protesters scattered before returning to a barricade. Some demonstrators tore out bricks from the sidewalk and smashed them.

The demonstration in D.C. had started at 5 p.m. with a crowd marching through the city, stopping once at the White House where a clash ensued. The crowed marched on and largely dispersed before a second protest at the White House erupted hours later, with demonstrators again facing law enforcement personnel in an atmosphere of tension. This included pulling and tugging at the metal barriers between officers and demonstrators.

Underscoring the intensity of the second confrontation, which continued past midnight, were the sounds of impact against the riot shields carried by the officers.

Tension seemed to reach a crescendo in the glare of bright lights, and then to subside again. The site of the protest was no more than 30 or 40 yards from the enclosed lawn of the White House grounds.

The physical nature of the confrontation and the lateness of the hour combined to make it particularly unusual. A similar event has not occurred there in years; it was not clear if the president and his family were in the White House at the time.

At the earlier White House demonstration, some protesters clashed with police, and a spokesman for the White House confirmed it was placed under lockdown as the demonstration grew outside. The lockdown was later lifted.

At both demonstrations, demonstrators tried to overturn the bike-rack style crowd control barriers, and water bottles were thrown during each of the two protests.

After leaving the White House following the first of the two demonstrations, protesters went to the Capitol, where as darkness fell some tried briefly to block the movement of a Capitol Police car. Tensions mounted, then seemed to subside.

Without injuries or arrests reported there, many demonstrators left the Capitol grounds and walked east, through the residential sections of Capitol Hill.

They then continued on a journey that eventually took them onto part of Interstate 695, then back to the vicinity of the Capitol and by about 10:30 p.m., once more into commercial areas of Northwest before they appeared to disperse.

As midnight approached it could not be readily determined how many of those taking part in the second protest had also been in the earlier one.

While the early evening demonstration was at the White House, at least two people were seen being taken into custody and water and plastic water bottles were thrown at officers, including uniformed members of the U.S. Secret Service.

Protests over Floyd’s killing reverberated across the country, including in Virginia’s capital. The Richmond Times-Dispatch reported a tense confrontation outside Richmond police headquarters. Windows on the building were broken and a car was set on fire.

The Washington protest had started peacefully with a rally at 14th and U streets in the District, and then proceeded south on 14th Street. A clash occurred with police shortly after demonstrators entered Lafayette Square, across from the White House.

It was not immediately clear what prompted the scuffle but it appeared officers took a man into custody and were then surrounded by demonstrators shouting, “Let him go.”

Officers pushed their way through the crowd to reach the scene and they then took the man into the nearby Freedman’s Bank Building, an annex for the U.S. Treasury. Several demonstrators scaled iron bars covering a large window and one scrawled in large letters an expletive referring to President Trump.

Demonstrators then returned to the park and squared off against a line of officers with the Secret Service and D.C. police, at metal barricades. More water bottles were thrown and at least one more person was seen being taken into custody.

The group left the White House area around 8 p.m. before returning later in the evening. Before the second demonstration broke up, some in the crowd shouted that they would continue protesting Saturday afternoon into the evening.

At the demonstration’s start protesters held signs and chanted, “I can’t breathe,” referencing some of the final words Floyd uttered while a Minneapolis police officer held him down to the ground for more than eight minutes with a knee on the back of his neck.

D.C. police stayed at a distance, keeping cars away. Then the crowd headed south on 14th Street.

Among them was Danicah Bethea, 28, a native of Chicago who now lives in Maryland. She said she had never protested before, but came out because she has “a black father, a black brother, a black man.”

Bethea said she was unable to watch the video of the officer with his knees on Floyd’s neck.

“I couldn’t bring myself to see a black person killed for no reason,” she said as she marched, holding a sign saying “Justice for George.”

The demonstrators recited a roll call of people killed by police or in police custody.

The demonstration was one of many around the country. Protests in Minneapolis over the past several days escalated into rioting, and a police station was burned.

Police chiefs from around the country have condemned the officers’ detaining of Floyd. On Friday, the officer seen on video with a knee on Floyd’s neck, Derek Chauvin, was arrested and charged with third-degree murder and second-degree manslaughter.

D.C. Police Chief Peter Newsham told The Post the incident in Minneapolis is “nothing short of murder.” Speaking separately to Fox 5 on Friday, Newsham and Mayor Muriel E. Bowser said they were expecting demonstrations and anticipated they would be peaceful.

Bowser called the death of Floyd “heartbreaking.”

“We saw a man begging for his life,” Bowser said. “We saw four officers watching it happen.”

Martin Weil, Dana Hedgpeth and Seung Min Kim contributed to this report