KUALA LUMPUR (Reuters) - Crowds of light motorbikes gun their engines in parts of the Malaysian capital after dark, as their young riders face off in impromptu races to decide who is the fastest and most skilful, sometimes with dozens of vehicles pitted against each other.
The illegal racers, or "Mat Rempit", as they are known to many Malaysians, hail mostly from the ethnic Malay majority, which forms about 60 percent of Malaysia's population of 30 million, with a sprinkling from its tiny ethnic Indian grouping.
Many conservative Malaysians frown upon the bike riders' decades-old culture, fearing the pastime's potential to encourage gambling, drug abuse, snatch thefts and sexual promiscuity, not to mention daredevil riding.
"There are some 'Mat Rempit' nowadays who race as a career, with rewards of money and the attention of young women," said one former rider, who asked to be identified only as Ziad, because of the sensitivity of the topic.
"They gather to look for trouble, and some even place bets on ramming through police roadblocks," he added.
The phenomenon has grown beyond its origins in gatherings of young people seeking the rush of adrenaline from riding at high speed, he said.
Police arrested as many as 467 people in 1,400 operations targeting the "Mat Rempit" and illegal motorcycle racing in 2011, the most recent year for which such data are available.
One stunt favored by more adventurous racers is the "Superman" pose, in which they zoom forward at well over 100 kph (62 mph) while lying flat on their seats, so as to cut wind resistance and get a further edge in speed.
More serious riders modify their bikes, trimming weight from already-light motorcycles with engine capacities of no more than 150 cc, and installing wheels that are barely an inch (2.5 cm) wide to ensure minimal ground contact.
The authorities' frequent crackdowns on the "Mat Rempit" have failed to discourage them, prompting a controversial proposal by the government in February to close off some city roads every weekend for legal races.
"It is not meant to encourage them to race, but to control the situation, because we are aware this is their only form of entertainment, due to the high cost of living," the Star newspaper quoted Federal Territories Minister Adnan Mansor as saying at the time.
The public and opposition politicians objected to the proposal, with one opposition member, Hannah Yeoh, saying the government was putting the "Mat Rempit" ahead of priorities such as overseas scholarship awards for top-performing students.
Reporting by Joseph Sipalan; Editing by Clarence Fernandez