MANILA (DPA) - Unclaimed mangled body parts from twin bombings at a cathedral in the Philippines' conflict-wracked south have boosted a theory that suicide bombers were behind the attack, the military said on Friday (Feb 1).

The death toll in the bombings at the Cathedral of Our Lady of Mount Carmel in Jolo town in Sulu province, 1,000km south of Manila, has risen to 22, after a 68-year-old woman died in hospital.

More than 100 people were also wounded in the twin blasts on Jan 27, which the authorities said were looking more likely to have been carried out by suicide bombers, after two sets of body parts recovered from the site remained unclaimed.

The body parts included feet, arms, torso and heads, said Colonel Noel Detoyato, a military spokesman.

"The pieces of body parts that are unclaimed and strewn all over the entrance as far as 50m away from the entrance supports the theory of a suicide bomber," he said.

The first bombing occurred inside the cathedral during mass, while the second explosion went off at the entrance as people fled and troops rushed in to respond to the initial blast.

A woman was believed to have brought one of the bombs inside the church, and a man carried the second explosive device outside.

Col Detoyato said the woman could have joined her partner outside after leaving the bomb inside the cathedral, just minutes before the second explosive device went off.

"I believe that's what happened, but we can only surmise," he said.

"Based on the body parts recovered, they are too close to the explosive that they were torn into pieces."