BELGRADE, Yugoslavia -- Sporadic clashes between Croatian forces and Serbian rebels have left at least 10 people dead since a cease-fire went into effect last week, including four in a Yugoslav air force attack, a senior federal official said Monday.
Irfan Ajanovic, a member of the Federal Commission for Cease-Fire Control, said there were several fatal clashes, but he called them 'only incidents, not big violations' that could jeopardize the truce.
'If we succeed in forming observer groups and posting them in conflict areas, I shall be a moderate optimist that we could solve the problem,' said Ajanovic, who also is deputy chairman of the Yugoslav federal legislature.
Since the 'absolute and uncontidional cease-fire' declared by the Yugoslav collective presidency went into effect at 6 a.m. Wednesday, at least 10 people have been killed in ethnic violence in Croatia, including a Croatian television cameraman, Ajanovic said.
In one incident, four Serbian rebels were killed Sunday when two federal jets attacked them by mistake at Topusko, 40 miles south of the Croatian capital of Zagreb, Ajanovic said. The two jets were sent by the Yugoslav military to retaliate for an attack by Croatian security forces at an army helicopter, he said.
The Croatian government and rebel Serbs were to have exchanged about 70 prisoners Monday, Ajanovic said, but the swap was canceled for a variety of reasons, in particular a 'lack of confidence.' Negotiations continued for their release, Ajanovic said.
He said members of the Federal Commission for Cease-Fire Control still must work out with Croatian leaders how to form federal observer groups and where to post them.
On Sunday evening, Croatian forces and rebel Serbs exchanged another 20 prisoners. On Saturday night, they traded a total of five men in the first such swap since the cease-fire was declared. The exchanges were organized with assistance from a Federal State Commission for the cease- fire control, officials said.
In one incident, at Beli Monastir near the Yugoslav-Hungarian border, rebel Serbs opened fire and wounded two Croatian policemen Sunday evening, the Croatian state-run Zagreb radio said.
Croatian police station official in Kutina, 50 miles east of the Croatian capital of Zagreb, said one of his men was killed and another wounded when unknown gunmen opened fire at a police patrol on a village road early Sunday.
At Slavonska Orahovica, 100 miles east of Zagreb, rebel Serbs fired at a three-man Croatian police patrol at 11 a.m. Sunday, killing Stjepan Mlakar, 31, and wounding another two policemen, Zagreb radio said.
Serbian guerrillas opened mortar fire Saturday evening and killed Ivan Rokic, a villager of Hrastovica at Petrinja, 31 miles southeast of Zagreb, the radio said.
At about 6 p.m. Saturday, Goran Lederer, 27, a cameraman for the Zagreb television, was shot and seriously wounded at Kostajnica, 60 miles southeast of Zagreb. Lederer died of wounds while being transported in an ambulance to Zagreb, television officials said.
In the past month in Croatia, a German journalist was killed and a number of Yugoslav reporters were wounded.
A number of incidents were reported Sunday in Serb-dominated enclaves of Croatia, despite the cease-fire that was to separate Croatia's National Guard and police forces from Serbian guerrillas.
The Yugoslav army, dominated by Serbian generals, was to play a buffer role, but Croatian officials have accused the federal military of siding with and assisting Serbian guerrillas.
More than 300 people have been killed in the past three months in Serb-Croat clashes in Croatia, where leaders of its 600,000 Serbs, fearing Croatian persecution, oppose inclusion of their enclaves in the republic's independence move. Croatia declared its independence June 25 from the six-republic Yugoslav federation of 23 million.
Contrary to the secessionist Slovenia and Croatia, which might accept an alliance of independent states as a solution to the crisis, Serbia, the largest republic, has insisted insisted on keeping the Yugoslav federation together.
Predominantly Roman Catholic Croatia and Slovenia are seeking independence from domination by mostly Christian Orthodox Serbia.