(CNN) -- Fighting raged between militants and security forces on a southern Philippine island where al Qaeda-linked militants are active, a top Filipino military official said Tuesday.
At least 11 people died, including three marines, a police officer, four civilians and three militants, according to Western Mindanao Command regional military commander Lt. Gen. Benjamin Dolorfino.
Dolorfino said about 25 suspected members of the Abu Sayyaf extremist group disguised in police and military uniforms launched attacks in Isabela City, the capital of the island of Basilan.
The militants carried out blasts near a church, a sports center and judge's house, and they traded gun fire with security forces.
Dolorfino said militants appeared to have been planning "something big" and believes security forces may have foiled a major attack. He said the militants may have been using explosives as a diversion to carry out a high-profile kidnapping. There were no immediate reports of any kidnappings, however.
Two suspected militants were injured and five more were captured. Authorities were interrogating them.
Troops are on the hunt for remaining militants that have fled the city.
Abu Sayyaf wants to establish a separate state for the country's minority Muslim population. The U.S. State Department considers it a terrorist organization and says it is linked to al Qaeda. The Philippines government has been fighting to contain the militants.
Abu Sayyaf is blamed for several terrorist attacks in the Philippines, including the bombing of a ferry in 2004 that left about 130 people dead.
CNN's Kathy Quiano contributed to this report.