ZAMBOANGA, Philippines, Feb. 20 (AP) - A Muslim rebel group said Tuesday it tortured an ailing U.S. hostage in retaliation for U.S. and British air strikes on Iraq.

``We will torture him more if they continue to attack other Muslims,'' said Abu Sabaya, the leader of the Abu Sayyaf guerrillas holding U.S. citizen Jeffrey Schilling hostage in the southern Philippines.

He told Radio Mindanao Network on Tuesday that the torture was in retaliation for U.S. and British strikes on long-range radar on Friday that they say Iraq used to target allied planes patrolling no-fly zones.

Sabaya has threatened several times to kill the 25-year-old Schilling, of Oakland, California, unless the group receives a $10 million ransom. Schilling was captured in August last year.

Sabaya has also said Schilling is very ill, losing weight and coughing blood.

Some local military officials, however, doubt that Schilling is a hostage and say he may sympathize with the Abu Sayyaf who are fighting to carve a separate homeland out of the southern region of Mindanao.

Schilling, a Muslim convert, was taken by the rebels after he visited their camp in Jolo on Aug. 31. Schilling was accompanied by girlfriend Ivy Osani, Sabaya's cousin. Osani was allowed to go after the rebels seized Schilling.

The Abu Sayyaf is the smaller but more extremist of two Muslim separatist groups in the south.

The group rose to international prominence last April when members crossed the sea border to Malaysia, abducted 21 Western vacationers and Asian workers from a dive resort and took them back to their camp on the Philippine island of Jolo. They later kidnapped other foreign and Filipino journalists covering the initial abductions.

Most of the hostages were freed, reportedly in exchange for huge ransoms. The rebels are now holding two captives, Schilling and Filipino dive resort worker Roland Ullah.

The government said last week that the number of Abu Sayyaf members increased by about 160 last year to 1,269.