The military earlier said that 15 people were killed Friday after heavy fighting between government forces and al-Qaeda-linked militants in the jungle region, where various Muslim extremist and bandit groups are active.
Three plantation workers including a father and son were shot dead in the southern island of Basilan yesterday in a suspected extortion attempt, said Senior Inspector Gean Gallardo, police chief of the island's capital.
"These three victims are just ordinary workers who have no axe to grind with anybody," he said.
The rebels had fired the mortars to drive off police and military men who were trying to arrest one of their commanders, he said.
More From This Section
The military had previously said six soldiers and nine fighters from the al-Qaeda-linked Abu Sayyaf extremist group were slain in fighting on Jolo island in the southern Sulu archipelago yesterday.
Regional military spokeswoman Captain Rowena Muyuela said the incidents were not directly linked. "They all involve different groups".
"These are all because of intensified law-enforcement operations," she told AFP.
Set up in the 1990s with seed money from Osama bin Laden's al-Qaeda network, the Abu Sayyaf, based in the islands of Basilan and Sulu, has been blamed for the worst terror attacks in the Philippines' history, including bombings and mass kidnappings of Christians and foreigners.
The group is believed to be holding at least 13 other hostages, including five foreigners, according the Philippine military.
The BIFF in turn are based in the major southern island of Mindanao and split from the main Muslim rebel group, the Moro Islamic Liberation Front (MILF), in 2008 as the MILF engaged in peace talks with the government.