MUSLIM extremist group Abu Sayyaf abducted seven construction workers early Monday, Sept. 14, on a government road project on the island of Basilan, the military said, according to Agence France-Presse (AFP).

Nine workers were initially abducted, but two managed to escape, said Capt. Sally Magno of the Joint Task Force Basilan, according to GMA News.

Workers were taking a water truck belonging to Abubakar Construction to Basilan on Monday at 8:45 am, when Abu Sayyaf intercepted the truck, according to Magno and a statement from Basilan’s military unit.

Police and troops were deployed to search for and rescue the workers, but were unable to find the suspects. The military and local officials are working to obtain further information on the abducted workers, said regional military spokeswoman Capt. Maria Rowena Muyuela, according to AFP.

The abduction of the workers comes days after a Basilan court declared Abu Sayyaf a terrorist organization under the Human Security Act of 2007, GMA News reported.

Abu Sayyaf is also blacklisted by the United States as a terrorist organization. The group has previously attacked Americans in the southern region.

The extremist group has a history of beheading its captives, kidnapping for ransom and fatal bombings, among other things. It has nearly 400 gunmen that divided into factions found in Basilan and other outlying islands, according to the Associated Press, and typically targets Christians and foreigners.