The bus, carrying 53 passengers, was traveling west from Iloilo City to San Jose de Buenavista in Antique province when it crashed into a concrete road barrier before plunging into a ravine of 15-meter depth around 4:30 p.m. local time in Hamtic town.
Junlee Saylo, head of the antique provincial information office, told a radio interview that 25 died on the spot and four others died at a local hospital.
The deaths include the bus driver and his collector, local news web ABS-CBN reported.
Quoting the Antique provincial government, Panay News, a regional newspaper, reported that two critically wounded passengers, including a male from Kenya, were taken to a hospital in Iloilo City for treatment.
Emergency workers have been rescuing the survivors and retrieving the bodies of the people in the ravine.
MNA/PR