Truce Violated 200 Times, Panel Reports : Yugoslavia: 70 dead in ethnic fighting since cease-fire was declared 2 weeks ago. Croatia hit by air strikes, mortar fire as battles go on unchecked.

The cease-fire declared two weeks ago in an attempt to halt ethnic violence between Serbians and Croatians in Yugoslavia has been violated more than 200 times, the national commission monitoring the truce said Friday.

The commission, which was appointed by the collective presidency of the divided nation, said 70 people had died in fighting since the cease-fire was declared on Aug. 7.

Battles continued unchecked across Croatia, which has been battered by air strikes, mortar attacks and street fighting, and the rival sides have accused each other of massacres and made exaggerated death claims.

The police chief of Sisak, southeast of Zagreb and the scene of repeated heavy fighting, denied a Croatian radio report that up to 200 Serb insurgents had been killed in one battle near the town Thursday and overnight.

Djuro Broderac said also that Serbian claims that Croatian forces had mercilessly cut down innocent Serbs were untrue. “Our people have not been doing this and will certainly not attack civilians,” he said.

Tanjug news agency said armed clashes continued for the fifth straight day in Pakrac, a mixed-population town at the heart of the conflict, in which Croatia claims that guerrillas are trying to stake out a Greater Serbia.

Tanjug said mortar rounds hit the town Friday and powerful explosions were heard. It added that a fire was raging at a woodworking factory, the town’s largest industrial plant, but most firefighters had already fled Pakrac.

Belgrade Radio said that Yugoslav army troops took control of some border crossings into Hungary from police, closing one crossing point, after a battalion of Croatian national guardsmen was routed and many fled into Hungary.

Members of the cease-fire commission said they were considering quitting because of the failure of the truce.

Bloody conflict has raged in three parts of Croatia, one of eight political subdivisions that make up the country, and Croatian President Franjo Tudjman gave federal leaders an ultimatum to curb actions by Serbian guerrillas and the federal army by the end of the month.

“The Yugoslav presidency should appeal to the republic of Serbia to stop immediately the organization and support for the armed uprising in Croatia which has as its goal the division of Croatian territory,” Tudjman said.

Also Friday, Croatia said that it would go on the offensive in a “dirty war” with Serbian guerrillas and army troops.

“We will launch offensive actions without any illusions because this is a dirty war,” Croatian Defense Minister Luka Bebic said.

“We are heading for a war which could be long-lasting, and we cannot afford to waste any more time,” he said at a news conference in the rebel republic’s capital, Zagreb.

Irfan Ajanovic, spokesman for the cease-fire commission, said at a Belgrade news conference that “we now have more flash points than before the cease-fire.”

“This is why I am reconsidering my position in the commission--because we are not in a position to fulfill our obligations. I think that other members are also of two minds.”

He said the main failure of the commission was that it had neglected to clearly identify the two sides in the conflict, an allusion to the republic of Serbia.

In a related development, officials in Budapest, Hungary, said a “strong protest” had been lodged with Yugoslavia because its fighter jets violated Hungarian airspace three times during missile attacks on Croatia, the Washington Post reported.

Eight MIG fighters allegedly flew nearly two miles into Hungarian territory Thursday at altitudes as low as 300 feet. Two of the MIGs allegedly fired missiles at Croatian villages while in Hungarian airspace.