Bosnian Serbs and Muslim-led government forces appear to be honoring their latest truce. Yet fighting has continued, leading to warnings that this cease-fire, too, could collapse.

Continued attacks on government troops in the Bihac area by rebel Serbs from neighboring Croatia and renegade Muslim forces have threatened the nationwide truce that took effect at noon Saturday.Neither the Croatian Serbs nor the rebel Muslims were party to the truce, brokered by Jimmy Carter.

Two government soldiers were wounded in the Bihac area Monday, said U.N. spokesman Lt. Col. Gary Coward. Shots rang out near the town of Velika Kladusa, one of the most contested front lines in the Bihac area, he said.

He said U.N. officials met with Croatian Serbs on Monday to try to persuade them to withdraw from the Bihac pocket, which is surrounded on three sides by Serb-held territory in Croatia.

Bosnian Serb leader Radovan Karadzic on Monday countered the criticism of his Croatian allies by charging that units from Croatia's army were fighting on the government side in western Bosnia-Herzegovina.

The United Nations said it had no evidence of Croatian troops fighting in Bosnia now, although it did confirm such involvement earlier this month.

"At the moment, we cannot substantiate Mr. Karadzic's claim," said Thant Myint-U, a U.N. spokesman in Zagreb, Croatia.

But both he and Coward stressed that they cannot monitor the cease-fire properly because U.N. movements are restricted in many parts of Bosnia.

Firing was heard around Sarajevo overnight, Coward said.

The truce brokered by Carter last week did not include Croatian troops or Bosnian Croat militias. But Coward said Bosnian President Alija Izetbegovic had promised U.N. officials to try to get his Croat allies to sign onto it.