Stunned by the deaths of five young people in three car crashes over the weekend, Montgomery County officials said yesterday that they will step up enforcement efforts against reckless driving and push for new laws aimed at keeping teenage drivers safe.

"We have to find a way to stop these needless tragedies from occurring," Police Chief J. Thomas Manger said at a news conference.

The crashes, all involving excessive speed and one involving drag racing, killed five young people and seriously injured four others, county police said. The victims were 16 to 19 years old.

"We'll use any tactic we can," Manger said, including deploying extra officers to monitor areas known to be gathering spots for young drag racers and perhaps employing a Maryland State Police helicopter to help with surveillance.

But local officials are limited in what they can do to combat reckless driving by teenagers, Manger and other officials said. Insurance industry analysts and two state legislators who have sought tougher restrictions on teenage motorists said Maryland's laws regarding young drivers are the weakest in the Washington region.

For example, Virginia and the District have laws restricting the number of passengers that new teenage drivers can have. A bill that would have imposed similar restrictions in Maryland failed in the General Assembly last year.

The drivers in the fatal crashes over the weekend were ages 16, 17 and 19. Two of the drivers were killed. In each of the three crashes, at least one young passenger was killed. Police said that all the accidents involved speeding and inexperience at the wheel.

State Del. Adrienne A. Mandel (D-Montgomery), who co-sponsored the bill dealing with passenger restrictions, said the state "needs to put more teeth into our law." She said she intends to "redouble" her efforts to impose passenger restrictions. For the last three years, attempts to impose such restrictions have failed, Mandel said.

In the District, a driver younger than 18 who has had a license for less than six months may not carry passengers unless one of them is a licensed driver age 21 or older. After six months, there may be no more than two passengers without supervision until the driver is 18.

In Virginia, a driver younger than 18 who has had a license for less than a year may not carry more than one passenger younger than 18. After a year, a driver younger than 18 may carry no more than three passengers younger than 18.

The reason is simple: Inexperienced drivers can be easily distracted, experts said. And young drivers sometimes try to impress one another.

"Young drivers often feel they are invincible," said David Snyder, vice president and general counsel of the American Insurance Association. "And because they don't fully understand the risks involved with a 3,000-pound motor vehicle at 60 miles per hour, they tend to focus on less important things, like the conversation with their peers."

Allan Williams, chief scientist for the Insurance Institute for Highway Safety, said that with young, inexperienced drivers, "there's a tendency toward risk-taking."

At James Hubert Blake High School in Silver Spring yesterday, news of the death of Alicia Betancourt, 16, spread sorrow through the halls.

Betancourt, a junior at Blake, died Friday night in an accident near Norbeck and Norwood roads in Aspen Hill. She was the passenger in a car driven by Hersh Kapoor, 16, who was critically injured.

At Atholton High School in Columbia, there was grief over the death of Robert Middaugh, 17, a senior. He died in a crash late Saturday night in Burtonsville. Also killed in that accident was Michelle Timchalk, 17, of Laurel.

Middaugh was driving a 2004 Pontiac GTO with three passengers on Sandy Spring Road about 11:30 p.m. when the car spun out of control and slammed into a steel light pole. Middaugh and Timchalk, who was riding in the front seat, died at the scene, police said. A back-seat passenger, Mary Kathleen Collins, 16, was severely injured.

In the crash that involved drag racing, police said, Edward Monterroza, 19, of Damascus was driving a 1991 Plymouth Laser with three passengers: Elmer Martinez, 18, of Wheaton; Rico Scott, 17, of Gaithersburg; and Alvin Monterroza, 16, of Montgomery Village.

Edward Monterroza and Martinez died when the Laser crashed in Poolesville early Sunday on a remote stretch of road. Police said that officers broke up a group of would-be drag racers and that Edward Monterroza was speeding away when the car went off the road.

For many of the friends and classmates of those who died over the weekend, it was a grim introduction to mortality.

"Many students are dealing with the death of a peer for the first time," said Michael Durso, principal of Springbrook High School, where Betancourt had numerous friends. "When someone is snatched right from your midst, someone in your age group, it's pretty sobering."

Staff writers Rebecca Dana and Ylan Q. Mui and researchers Carmen Chapin and Julie Tate contributed to this report.

Alicia Betancourt, a junior at Blake High School in Silver Spring, was killed late Friday.