Mannar, Sri Lanka ? Sri Lankan troops in boats and helicopters battled Tamil rebels Saturday, and witnesses accused government forces of opening fire in a fishing village, killing five people – one inside a church – and wounding dozens.

The surging violence heightened fears that the island nation was moving toward a return to all-out civil war.

The past several days have seen the worst violence since a 2002 cease-fire between the government and the Tamil Tigers, who control much of Sri Lanka’s north and east.

Tamil Tiger rebels said they had killed 12 soldiers; the navy said three sailors were killed and eight were missing.

The military said up to 30 rebels were killed in the fighting, but rebels acknowledged only two wounded.

Saturday’s bloodshed started when rebels attacked a navy base in the northwestern fishing village of Pesalai, triggering battles that forced about 200 ethnic Tamils to seek refuge in a Roman Catholic church.