Manila: Suspected Al Qaida-linked militants bombed a Roman Catholic cathedral compound and a bank in the southern Philippines on Sunday, police said. No one was injured in the blasts.

Police have been placed on the highest level of security following the dawn explosions in Zamboanga city, regional police Chief Superintendent Jaime Caringal said.

Zamboanga, south of Manila, is home to US troops providing counterterrorism training to Filipino soldiers, and the military says more than 300 Al Qaida-linked Abu Sayyaf militants are based in the area. The Abu Sayyaf appear on US and European terrorist lists for ransom kidnappings, beheadings and bomb attacks.

Caringal said a mortar round exploded under a car in the parking lot of the Immaculate Conception Cathedral, damaging two cars.

A church caretaker saw three men fleeing the scene on a motorcycle shortly before the blast, Caringal said. The caretaker said the men talked in a dialect spoken on Jolo, a mostly Muslim island.

Police suspect the men were Abu Sayyaf or Jemaah Islamiyah militants, Caringal said.

Caringal said the men were seen fleeing toward downtown Zamboanga, where 15 minutes later another mortar round exploded outside a bank, damaging the building's wall.

Zamboanga, a predominantly Christian city, has seen sporadic bomb attacks in past years, including one blamed on the Abu Sayyaf that killed a US Green Beret in 2002.