At least three people were killed while 13 were injured after a bus they were riding hit a truck and crashed on a portion of the North Luzon Expressway in Valenzuela City before dawn Thursday.

Investigators are verifying claims by the bus' passengers that the bus driver fell asleep at the wheel shortly before the accident.

"Yung initial report tatlo ang namatay at nasa 13 ang sugatan," NLEX traffic control supervisor Ariel Salita said in an interview on dzBB radio.

He said the incident occurred at about 4:50 a.m., involving a Genesis bus and a 16-wheeler truck.

Citing initial testimonies from the passengers, Salita said the bus hit the truck before going out of control and crashing at the side of the road.

"Ang initial report, nakatulog ang driver ng Genesis bus, pero hindi confirmed ang impormasyong ito," he said.

A separate report by dzBB's Allan Gatus said the incident occurred on the southbound part of NLEX near the Torres Bugallon overpass.

The bus (body number 81879) had a crumpled front due to the impact of the truck.

"Palundag-lundag tapos bigla kami bumangga, papreno-preno siya, biglang punta kami sa sulok. Tapos sira na upuan namin, subsob kami sa harapan," one of the injured passengers said.

The dzBB report also said the bus had bloodstains in the interior, and the seats were in disarray.

On the other hand, truck driver Elmer Gomez said he was willing to give his side on what happened.

Gomez was quoted in the report as saying it was not his fault as the bus hit the truck he was driving. He added he had no intention to flee.

The dzBB report said the truck was carrying sand and was on its way to Parañaque City. — LBG, GMA News