KORONADAL CITY, Philippines – Three family members were killed in grenade attack in Sulu on Tuesday night, police said.

Killed in the blast in the town of Talipao were Salim Ladjabasal and his two sons, Al-Anser and Ken, said Chief Superintendent Bienvenido Latag, Autonomous Region in Muslim Mindanao police director.

Latag said Ladjabasal’s wife and two other kids were hurt.

“Our policemen are investigating the incident. They were sleeping when armed men fired grenade launcher towards their house,” Latag said.

No one claimed responsibility for the attack but authorities blamed Abu Sayyaf militants in previous incidents.

The Abu Sayyaf group, founded in the early 1990s by Islamic extremists, is notorious for kidnappings, bombings and even beheadings in Mindanao over the past decade. The group was blacklisted by the US as a foreign terrorist organization.