At least 22 people were killed when a speeding commuter bus crashed off an elevated motorway onto a delivery van in the Philippine capital, Manila, early on Monday, emergency authorities said.
At least a dozen bodies had been pulled from the twisted debris of the overturned bus, police spokeswoman Elizabeth Velasquez told reporters.
"It was not clear how this accident happened," she said.
One witness reported seeing the bus speeding in poor weather.
Rescue workers were still pulling bodies from the wreckage in a Manila suburb and at least 20 injured people had been rushed to hospital, Velasquez said.
The Philippines is notorious for its poor traffic safety record, as well as for its snarling lines of traffic in major cities.
In 2011, the Asian Development Bank said nearly 1,900 people had been killed in more than 85,000 road accidents in the Philippines.
Monday's crash caused traffic chaos in the sprawling city of 11.5 million people.
While police said they were investigating the cause of the crash, one witness told Philippine radio she saw the bus speeding past moments before the crash.
"I was driving at 80 kph (50 mph) because it was still dark and raining when this bus overtook us," the woman, who gave her name as Irene, told dzMM radio.
"It was probably running at more than 100 kph (60 mph). "Minutes later, I saw the bus fell off the highway. The railings on the highway were also gone."
Transportation authorities immediately halted all other services run by bus Don Mariano Transport, saying it had figured in an unspecified number of road accidents since 2011.