COTABATO (Philippines) - FOUR people were killed and 34 wounded in a bomb attack outside a Catholic church in the strife-torn southern Philippines Sunday, police and military said.

The bomb exploded as churchgoers were filing out of the Immaculate Conception cathedral in Cotabato city after an early morning mass, police said.

City police chief Superintendent Willie Dangane told AFP that one body was recovered from the debris. Two others were recovered about an hour later, while a fourth died in hospital, police and hospital sources said.

Two of the dead were soldiers guarding the church, police said. A man described as the possible bomber was arrested minutes after the blast, as he allegedly tried to bring a second bomb inside the church, a police source said.

Froi Cordero, a priest who helped take the wounded to hospital, said many of those being being treated for blast wounds were women and children.

City mayor Muslimin Sema said the number of wounded had reached 34, as he ordered stepped-up security to prevent further attacks.

Nobody has claimed responsibility for the attack, but regional military spokesman Lieutenant Colonel Jonathan Ponce was quick to blame separatist Moro Islamic Liberation Front (MILF) rebels for the blast.

He said a bomb also allegedly planted by MILF rebels exploded in the nearby town of Datu Piang late on Saturday, wounding three people.

The 12,000-strong MILF broke a five-year-old ceasefire in August 2008, launching deadly attacks across several towns and provinces in Mindanao after a court rejected a proposed deal with the government that would have given them control over vast lands they considered as 'ancestral domain.'

Fighting that followed left nearly 300 civilians and combatants dead, while more than half a million were displaced. -- AFP