Bosnia Combatants Stop Surrendering Big Guns to U.N. : Balkans: Effect on Sarajevo cease-fire is unclear. Meanwhile, peace talks in Geneva break up with no progress reported.

Government and Bosnian Serb fighters who had just begun surrendering their big guns to the United Nations stopped Saturday, but whether that was only a hitch in the 2-day-old truce or a more dangerous sign remained to be seen.

The day was full of ominous developments.

* Despite U.S. and Russian pressure on the warring sides, peace talks in Geneva broke up with no progress reported, raising further doubts about the viability of the Sarajevo cease-fire.

* The U.S. State Department ordered the families of American diplomats and government employees to leave Yugoslavia immediately, embassy officials in Belgrade said.

The decision was precipitated by NATO’s ultimatum to Bosnian Serbs to withdraw their heavy weapons from Sarajevo by midnight Feb. 20 or face air strikes. Many in Serb-dominated Yugoslavia support the Bosnian Serbs, and the U.S. government apparently is worried about a backlash against Americans if the air strikes are carried out.

* Bosnian Serb TV showed film Saturday night of camouflage-clad fighters aiming shoulder-held ground-to-air missiles at imaginary NATO planes.

Displays of bluffing and brinkmanship have characterized war and peace in the Balkans, and it was unclear whether Saturday’s developments meant that the latest of numerous cease-fires was in danger of collapse.

The Serbs, while chafing at the NATO ultimatum, agreed as part of Wednesday’s cease-fire to pull back their heavy weapons and put them under U.N. supervision. The order also applied to Bosnia’s Muslim-led government.

After handing over several mortars and other big guns at Sarajevo-area barracks Friday, neither side turned in any weapons on Saturday, said Maj. Jose Labandeira, a U.N. spokesman.

The Bosnian army turned over five guns Friday but decided to keep the rest for now, saying the Serbs had 10 times as many but had turned in only 13.

“They have many more weapons than we do, so they must hand in many more,” said Gen. Jovan Divjak, the deputy Bosnian army commander.

Divjak charged that the Serbs had withdrawn their big guns from the 12-mile zone around Sarajevo but were hiding some or taking them to other battle fronts.

Sarajevo was unusually peaceful, although a tank shell that landed near downtown Saturday afternoon injured two people.

French peacekeepers have camped out at six flash points of the Sarajevo fighting since Thursday, and Friday night was the quietest in months.

The French soldiers began working to restore electricity to the city, a repair job that will take at least 10 days if peace holds.

“Once all the lights are on, life will be transformed,” said Lt. Gen. Michael Rose, the new U.N. commander in Bosnia.

In the meantime, Sarajevans who wanted to watch the opening of the Winter Olympics in Lillehammer, Norway, had to hook up portable TVs to car batteries or watch at the few places that had electricity. The 1984 Winter Games were held in Sarajevo.

“I feel terrible when I remember all the beauty during the Sarajevo Olympic Games,” said Ismet Kaminlija, an army captain who watched the ceremony from a hospital bed, where he was recovering from a machine-gun wound.

Rose’s peacekeepers were thin on the ground--about 30 at each cease-fire line--but 150 Malaysian reinforcements arrived in Sarajevo, while others set up at Bosnian Serb positions in the mountains.

On Mt. Trebevic, southeast of the capital, French Lt. Lionel Paillot and his infantrymen moved into a burned-out restaurant.

Milenko Blagojevic, a Bosnian Serb machine-gunner nearby, said he didn’t think NATO would bomb his position. If it does, he said, “The people here will kill those French with axes and knives.”

But Rose said the U.N. troops were there to stay.

“The troops who have been put on the ground between the warring elements will not go back,” he said. If fired on, “they will fire back. But that won’t happen because people want peace.”

Saturday marked the one-week anniversary of the mortar shell explosion at Markale market that killed 68 people, injured 142 and led NATO to issue its ultimatum.

In northwestern Bosnia, Serbs and Bosnian army troops battled on the Grabez plateau near Bihac, according to U.N. spokesman Lt. Col. Bill Aikman.

Bosnian government radio said that Bosnian Serb fighters fired on mosques in the towns of Cazin, Bihac and Ostrozac and that a number of civilians were killed. The report could not be confirmed.

Croats fired 69 shells into the Muslim sector of Mostar, in the south, Friday night, Aikman said.