Guns Still Roar in Balkans as Talks Continue in Geneva : Combat: Strategic bridge comes under Serb fire. Snipers kill 3 in Sarajevo despite cease-fire.

ZAGREB, Croatia —  Peace seemed as distant as ever in the Balkans on Sunday as artillery, tanks and foot soldiers continued to wage war for territory in Bosnia and rebel Serbian gunners opened fire on a strategically located bridge in southern Croatia.

In Sarajevo, Bosnia’s Serb-encircled capital, where a cease-fire supposedly has been in effect since Friday, snipers aided by a full moon killed three people and wounded five others as they tried to move in and out of the city by crossing the U.N.-controlled airport.

And at peace negotiations in Geneva, Bosnian government leaders voiced dissent about a preliminary accord with Serbs and Croats, and their Muslim president threatened to leave the talks if Serbs do not curb attacks on Bosnian towns.

In Bosnia, heavy fighting was reported in two locations, including a triangle north of Sarajevo touching on the city of Zvornik on the Serbian frontier. According to Sarajevo radio, the battle began when Serbian infantry backed by artillery and tanks tried to overrun Muslim positions.

“The Zvornik front is a veritable inferno today,” the radio said. “Thousands of highly destructive missiles are landing on the forward defense lines and are obliterating villages.”

In Belgrade, official Serbian media blamed the Muslims for the fighting. Serb-controlled radio said a Muslim infantry attack had been repulsed in Doboj.

On Saturday, soldiers loyal to Bosnia’s Muslim-controlled government seized a pair of villages in the republic’s rugged central region from ethnic Croats. On Sunday, Croatian radio reported Muslim artillery fire on Croat positions near Novi Travnik and fighting near Prozor, which it described as the most recent actions in the Muslims’ campaign to capture the key town of Gornji Vakuf.

Despite the cease-fire, 11 people have been killed in central Bosnia and at least twice that number wounded since last Friday, Croatian radio said.

A dispute between Serbs and Croats also revived hostilities on Croatian soil, although they could prove to be short-lived. Rebel Serb gunners fired at least 20 artillery rounds at the pontoon bridge spanning the Maslenica inlet on the Adriatic coast Sunday afternoon.

Under terms of a U.N.-brokered accord, at midnight Saturday the Croats were supposed to hand over the bridge, the only span linking central Croatia with the Dalmatian coast, to U.N. peacekeepers, along with a nearby airport and other positions.

Last week, the Zagreb government affixed a new condition to the withdrawal--confinement to U.N. arms depots of the Serbian artillery trained on the bridge from the adjacent Krajina enclave.

The Croats did nothing to prepare for the transfer, the disgusted U.N. military commander Gen. Jean Cot charged Saturday. It was almost inconceivable anyway that the government of President Franjo Tudjman would agree to give up the 890-foot bridge that it reopened with such patriotic hoopla two weeks earlier on land reconquered last January.

“For sure we will not withdraw,” one Croatian defender told a visiting Western reporter. “We lost too many people to give this land back.”

U.N. officials say they doubt that the Serbs intend to destroy the bridge, because it is in a crucial location and they command the heights controlling it.