AMBON, Indonesia (AP) _ Three civilians and one soldier were killed in a fresh outbreak of religious violence in the eastern Indonesian town of Ambon, the military and witnesses said.

An unspecified number of civilians were injured and at least 23 houses were set ablaze.

Military spokesman Lt. Col. Iwa Budiman said Lt. Ricky Kalalo was shot in the head while heading to disperse the clash between Christians and Muslims that began dawn Monday in the Batu Merah neighborhood.

``It is still not clear whether he was shot by another soldier or an armed civilian,'' Budiman said.

Witnesses said the other three victims _ two Muslims and a Christian _ also died of gunshot wounds. Sporadic shots and explosions of homemade bombs were heard in the area until Monday afternoon.

Budiman said some of the rival Muslims and Christians have used ``sophisticated homemade guns'' in the sectarian conflict that has been plaguing the region since January.

The new clash caused tensions in other parts of Ambon, the capital of Maluku, an Indonesian province known as Spice Island during Dutch colonial rule.

More than 500 people have been killed in the conflict that first broke out in Ambon, about 1,440 miles northeast of Jakarta, and spread to other islands of the province.