The Muslim extremist group Abu Sayyaf (search) claimed responsibility Sunday for a ferry explosion and fire that killed at least two people, though 180 more were missing, according to a radio report.

The Radio Mindanao Network said Abu Sayyaf spokesman Abu Sulaiman claimed Friday's explosion was revenge for government attacks in the southern Mindanao (search) area. Abu Sayyaf has often called the radio network in the past.

Fire raced through the Superferry 14 on Friday shortly after it left Manila (search) for central and southern islands, killing one person and injuring 12 others. Witnesses reported a powerful explosion that sparked an inferno.

The fire occurred the same day that two alleged Abu Sayyaf members were convicted of kidnapping an American in 2000 and another was arraigned in a separate mass abduction.

Radio Mindanao did not air the claim, but reporter Benji Alejandro said he first received a claim of responsibility via a mobile phone text message Friday morning and asked the sender to call to verify the allegation. Joel Sanson, the network's program director, said he also had been called and recognized Sulaiman's voice.

Sanson quoted Sulaiman as saying: "They have been warned before but they never listened."

There was no immediate reaction from the government.

Officials have not speculated on the cause of the fire, but said they could not rule out terrorism even though police dogs checked the ferry before it left Manila. Witnesses have said the blaze was triggered by an explosion at 12:50 a.m., two hours into the ferry's regular trip to the central and southern Philippines.

Police intelligence reports have said the ferries, one of the main forms of inter-island travel in the sprawling archipelago, were potential targets of Abu Sayyaf, a group on the U.S. list of terrorist groups.

After being turned back by intense heat and smoke a day earlier, coast guard divers entered the partially submerged ship Sunday through broken.

Coast guard officials said 565 passengers and 153 crew members jumped into the sea or boarded lifeboats and were rescued as the fire raged through the 10,192-ton steel-hulled ferry at the mouth of Manila Bay.

Rescuers found one body after the fire broke out but 180 people are missing, leading some officials to speculate that they may have been trapped in the inferno that engulfed the giant vessel.

President Gloria Macapagal Arroyo (search) said search efforts "will not be called off until all of them are accounted for."

"The authorities will get to the bottom of this incident ... and take steps to ensure it does not happen again," she said in a statement, urging stricter implementation of maritime laws.

Relatives of the missing waited outside Manila's coast guard headquarters to hear any news of their loved ones.