ZAMBOANGA, Philippines ? Gunmen abducted four sailors from an Indonesian barge and tugboat sailing by the southern Philippine island base of Muslim extremists, coast guard officials said today.

The barge was left adrift near the islet of Tamuk, which is just off the Basilan island base of Abu Sayyaf rebels who have abducted three Americans and almost 100 Filipinos in the past year.

The rebels are known for carrying out sea-borne raids but officials did not immediately name any suspects.