The streets of downtown Hanoi had emptied of all but a few late night revelers.

By midnight, on a recent Saturday, a light rain had dried up and the chilly dampness of winter gave way to a fresh Spring evening.

In the crisp quiet of the city, the loop around Hoan Kiem Lake buzzed with motorbike engines and teenage angst.

By 1 a.m., some 60 youths had gathered, in leather jackets and dark clothes, on Dinh Tien Hoang Street, on a broad stretch of sidewalk in front of the Water Puppetry Theater.

Some chatted with their girlfriends. Others gathered in small groups. Some smoked, anxiously, astride their motorcycles.

A handful of daredevils tore up the road, zigzagging across lanes and yanking their bikes up into daring wheelies as they passed the more cautious crowd of cyclists.

“They’re waiting for the police to go home,” said Thi, a French-speaking tour guide who grew up just a few blocks away.

Thi said he’d never raced, but for the past three years, he’d come out on Saturday nights to watch the spectacle. He said the racers had lookouts posted all over the two kilometer loop.

When the police go home, he said, they all get the signal and burn out into the fray. Some drive down the road lying flat on their motorbike cushions. Others drive standing up, manipulating the handlebars with their feet.

There had been injuries and deaths, he claimed.

Attempts to confirm the claim with local police and hospitals were not successful.

An hour passed and only a few kids left the sidewalk to race or pull tricks around the lake.

The remaining crowd seemed anxious and bored.

At around 1:45 a.m., the real race began.

A green troop transport lumbered onto the opposite corner sending the group into an ecstatic frenzy. By the time the first cop had hopped over the rear gate, clutching a white baton, the kids had jetted around the corner, heading north in a speeding swarm.

Street racing is everywhere in Hanoi, but Hoan Kiem Lake seems an unlikely space for racing. The lake is prime real estate: inhabited by an exalted turtle and surrounded by posh shops, restaurants and strolling tourists.

One newspaper editor in the town scoffed at the suggestion. “There are races,” she said. “But not around Hoan Kiem.”

Two years ago, however, Dr. Alexandre Dormeier Freire published a sociological study on Vietnamese motorcycle culture that identified Hoan Kiem Lake as a place to show off.

Within the culture of racers and daredevils, the most popular pastime, Freire noted, was toying with the police.

“Provoking the police force is a rather widespread practice,” he noted.

And the cops aren’t happy about it.

“The illegal racers often go out on Saturdays and Sundays, when there are fewer patrols,” admitted Senior Lieutenant Colonel Pham Van Hung, Chief of the Mobile Police Regiment at the city police force. “We are aware of the situation and plan to resolve it.”

Now that the weather has begun to warm up, he said that the seasons for weekend racing and stunt driving has returned, he said. They will dispatch more police to combat the issue.

Some young Vietnamese say that the approach has been counter-productive: police pursuit can result in terrible crashes.

The few who are caught face stiff penalties.

This January, the Hanoi People’s Court tried 21 youths, in eight different groups, for participating in a November street race.

Several defendants, some of whom were still in high school, were sentenced to between three and 13 months in jail.

“The municipal People’s Court will try three more racers, soon, for similar crimes,” said Hung, the police official.