Skirmishes between Muslims and Croats threatened a new cease-fire Friday, but fighting eased in Serb-dominated regions.

A Canadian U.N. peacekeeper was killed in fighting near Sarajevo, 40 minutes after the noon cease-fire was supposed to silence guns across Bosnia.Cpl. Daniel Gunther, 24, of Val-Belair, Quebec, died in Buci, about 12 miles northwest of the Bosnian capital in an area of high Muslim-Croat tension.

U.N. officials said it was unclear who was responsible, but the Bosnian army said he was killed by a Serb mortar round.

A U.N. spokesman in Sarajevo, Capt. Jes Frederiksen, said the soldier was killed when a U.N. armored personnel carrier was hit by anti-tank fire.

He was the 47th peacekeeper killed in the former Yugoslavia since U.N. troops arrived in March 1992.

Croatian radio reported fighting late Friday in or near the Bosnian towns of Vares, Visoko and Novi Travnik.

Tension also continued between Croat and Muslim-dominated Bosnian government forces in the southwestern town of Mostar, scene of fierce fighting between the two erstwhile allies in the past two months.

"We have not seen any reduction of fighting," said Cmdr. Barry Frewer, a U.N. spokesman in Sarajevo.

The cease-fire accord was signed Tuesday by top military commanders of Bosnia's warring parties. It is the fourth nationwide truce of Bosnia's 15-month-old war. Previous truces have collapsed quickly.

Eastern Bosnia, gripped by weeks of battles between Serbs and Bosnian troops, was relatively quiet. There were sporadic explosions on the outskirts of Sarajevo.