Eleven were killed in an encounter between government soldiers and members of the bandit group Abu Sayyaf in Patikul, Sulu on Saturday.

Western Mindanao Command spokesman Col. Rodrigo Gregorio said the gun battle started around 6:40 a.m. in Barangay Tugas.

The encounter left seven soldiers and four bandits dead and 10 others wounded. According to Gregorio, two of the four slain Abu Sayyaf members were identified as Commander Apong Idol, a mid-level bandit leader, and Kausar Sawadjaan.

Gregorio said the troops from Force Reconnaissance Class-18 encountered a group of Abu Sayyaf bandits while the soldiers were carrying out rescue operations for Casilda Villarasa, wife of a non-commissioned Marine officer assigned in Sulu.

Villarasa, 41, is a medical technologist at the Integrated Provincial Health Office in Jolo. She was on her way to work with her nine-year-old daughter when seized by the bandits. Her daughter managed to run away.

Security forces are on full alert in the province after the clash.

The government suffered heavy casualties as the soldiers engaged in the operation are undergoing training for Force Reconnaissance Unit of the Philippine Marines. The course includes a test mission which is an actual combat operation. A similar encounter in 2007 killed 15 Marines undergoing Force Reconnaissance Class-13 in Basilan.

The ASG along with other bandit groups operate mostly in Basilan and Sulu in Southern Philippines. These groups are responsible for kidnap for ransom and extortion activities in their area.