The low-level eruption, which sent a plume of steam billowing 2,400 metres (7,900 feet) skyward from Lake Taal volcano, came a week into the search for the remains of people allegedly killed by rogue police for their involvement in fixing cockfights.

"The (dives) were temporarily terminated," an official involved in the search who spoke on condition of anonymity told AFP, adding a number of divers had been in the water at the time of the eruption.

The Philippine Institute of Volcanology and Seismology said the volcano had experienced "minor phreatomagmatic eruptive events" just after 3:00 pm (0700 GMT).

The agency's Mara Antonia Bornas said the volcano had been at a low alert level since 2021 and that no major eruptions were predicted.

The divers would not be affected, and only the volcano island in the middle of the lake was "under precaution", she said.

Since beginning the search on July 10, the Philippine Coast Guard has found five bags at the bottom of the lake, some of which may have contained human bones.

Police are conducting forensic testing to determine if the bones are human and if they match the DNA of the missing cockfighters.

Fifteen police officers are under investigation over the spate of mysterious 2022 disappearances in the country's huge cockfighting industry.

The case erupted back into the public consciousness last month with the televised appearance of a witness claiming to know where bodies had been submerged in Lake Taal.

Located about two hours south of Manila, the lake spans more than 230 square kilometres (89 square miles) and reaches depths of 172 metres in some places.

Filipinos from all walks of life wager millions of dollars on matches every week between roosters who fight to the death with razor-sharp metal spurs tied to their legs.

Cockfighting, banned in many other countries, survived coronavirus pandemic restrictions by going online, drawing many more gamblers who use their mobile phones to place wagers.

Former president Rodrigo Duterte banned the livestreaming of cockfights shortly before leaving office in 2022, but it has continued due to lax enforcement.