BANGKOK, THAILAND — Seven people were killed yesterday afternoon when a racing bus slammed into pedestrians and vehicles at the Bang Na intersection. Police called it one of the most horrific accidents in Bangkok in recent times.

The driver of a No 1141 bus was racing with another bus along Bang Na-Trat Road when the vehicle's brakes apparently failed at the junction with Sukhumvit Road.

The two buses were racing to a stop where lots of fares were waiting.

The bus ploughed across a traffic island, uprooting trees and power poles before ramming into a van, a pick-up truck, another bus and a passenger car that were waiting at traffic lights.

Four pedestrians — all of them women — were killed, two other women were crushed to death in the passenger car, and a passenger in the van was critically injured and died later in hospital.

None of the 20 passengers on board the No 1141 bus was seriously hurt. Some of the passengers in the No 45 bus that was hit suffered slight injuries.

I approached the bus driver and slapped him ... I asked, "Do you know how many people have died?"

"I heard many people scream in pain. It was so horrible," said Chalor Boonyoo, who owns a grocery in the area. "The bus simply lost control. It swerved and virtually destroyed everything in its path."

The bus driver, Sombat Trakutwat, 30, was arrested. Initial tests found no evidence of drug use, but police yesterday were awaiting the results of an alcohol test. Sombat claimed the accident occurred because his brakes failed.

"I was aware of it just before I reached the curb. The bus wouldn't stop. I saw crowds of pedestrians so I chose the traffic island. I did my best. There could have been more deaths," he said.

Sombat admitted that he was involved in a previous accident when driving a 10-wheel truck, in which there were casualties. Witnesses of yesterday's horror said Sombat was driving at high speed and was racing a No 365 bus on an outer lane of the Bang Na-Trat Road. The two buses were racing to a bus stop just beyond the intersection on Sukhumvit Road, where a lot of commuters were waiting.

"It was a mad race between the two buses," said a man who owns a newsstand at the scene.

"After the accident I approached the bus driver and slapped him on the head. I asked, 'Why the hell did you drive like that? Do you know how many people have died?' He looked dazed and did not answer."

"This is a chronic problem ... the drivers behave for a day or two, then start racing for passengers again."

Other witnesses said racing for passengers by drivers operating on concession licences was notoriously common in the area. They also accused certain drivers of drug or alcohol abuse.

"They are disasters waiting to happen," said one vendor. "Sometimes you get on a bus and see a driver with filthy clothes and messy hair and all you can do is pray."

The four pedestrians killed could not be immediately identified. The two women crushed in the Toyota passenger car were identified as Wipa Rojrungthawee, 31, and Buntarikka Lattiranont, a 27-year-old doctor at the Phra Pradaeng Hospital.

"She was a good girl," said Buntarikka's mother. "She just graduated and had a very bright future."

Calls were made yesterday for civil suits against the bus companies.

"This is a chronic problem," said Kit Potisukko, deputy director of the Bangkok Mass Transit Authority. "When we crack down, the drivers behave for a day or two, then they start racing for passengers again."

[Thanks to Gary Crosse for this contribution.]