Rescuers conduct a retrieval operation after a bus carrying dozens of people fell off a cliff in Antique on Tuesday. Reuters

Seventeen people died and 11 were injured when a passenger bus careered off a road on a "killer curve" and plunged down a mountain in the central Philippines, officials said on Wednesday.

The bus was travelling in Hamtic municipality in Antique province when the crash happened Tuesday afternoon, provincial disaster agency head Roderick Train told the media.

Seven people were in critical condition in hospital and four others were stable, Train said, describing the section of road as "accident prone."

One Kenyan national was among those killed, and a second Kenyan was among those critically injured.

Governor Rhodora Cadiao earlier told radio station DZRH there were four Kenyans on board the bus that was carrying mostly residents of Antique.

Local police later clarified there were only two. Another body was still being identified.

"I call that place 'killer curve'... it was already the second Ceres bus that fell off there," said Cadiao, referring to the bus company.

"With the many number of deaths that road must be abandoned... and make another road to make that area safe."

The heavily forested ravine was around 30 metres deep, Cadiao said.

Train said the bus "fell from a high place," resulting in many casualties.

"Based on the witnesses, it was a mechanical failure. The driver lost control, possible brake failure," Train said.

Cadiao visited the hospital where survivors were being treated for their injuries. She promised government assistance for medical and funeral expenses of victims.

Train said the search and rescue operation had finished and authorities would now focus on retrieving the bus.

"We searched for the bodies until this morning," Train said. "It was tiring to go up and down."

Deadly road accidents are common in the Southeast Asian nation, where drivers frequently flout the rules and vehicles are often poorly maintained or overloaded.

Local media had reported earlier than 28 died in the crash.

"We call that area the killer curve. It was already the second bus that fell off there," Cadiao told DZRH radio station.

Rescue operations at the site have stopped after all visible bodies were retrieved, the Antique government said on Facebook.

"The engineering design of this road is very faulty," Cadiao said. "I want to condemn that road already."

The Philippines is notorious for its lax regulation on public transportation and poorly maintained roads.

Agencies