President Benigno Aquino linked for the first time Islamic militants and breakaway Muslim rebels Thursday to a recent spate of deadly bombings in the Philippines.

A total of 14 people were killed in two blasts on the southern island of Mindanao on July 26 and August 5, with 76 others wounded in the attacks. Seven soldiers were also wounded in a roadside bomb attack in Mindanao on Wednesday.

The authorities now believe the attacks were linked to security operations against the Abu Sayyaf Islamic militant group and the Bangsamoro Islamic Freedom Fighters (BIFF), Aquino said in the Mindanao city of Davao.

"There is a theory that all of these bombings are related to that, to lessen the pressure of ongoing follow-up operations against these BIFF elements," he told reporters on the sidelines of a business conference.

Aquino did not say outright if Abu Sayyaf and BIFF are directly behind the recent Mindanao bombings.

But he said the security services are looking into growing links among three "threat groups" that he did not identify.

"Previously they were in some sort of a loose alliance, but now they are working together in a desperate bid to halt the peace process in Mindanao," Aquino said.

The leader of the BIFF had been expelled from the Moro Islamic Liberation Front, which later signed a preliminary peace agreement with the national government last year.

Aquino hopes to sign a final peace treaty with the MILF before he leaves office in 2016 that would create an autonomous Muslim area in the south of the mainly Catholic nation, and end decades of conflict that have claimed 150,000 lives.

Three members of the BIFF, which opposes the MILF peace talks, were killed in a skirmish with the military in Mindanao last week.

Aquino said there are also ongoing operations against the Abu Sayyaf, blamed for the deadliest bombings in the country as well as kidnappings of foreign tourists and missionaries.

On the neighbouring southern island of Basilan on Thursday, a soldier was killed and eight others slightly wounded in an assault of an Abu Sayyaf hideout, the military said.

The dawn raid turned up mortar shells, improvised explosive devices and other bomb-making materials, said Colonel Carlito Galvez, the island's military commander.

"The Abu Sayyaf planned to use these after the Ramadan," said Galvez, referring to the Muslim fasting period which ended Thursday.