Sarajevo Shelled; at Least 35 Die : Balkans: The deadliest mortar attack on city in more than 18 months brings U.S. call for retaliation against the Bosnian Serbs. But U.N. says it’s not sure who fired.

A mortar attack on the heart of Sarajevo, the capital of Bosnia-Herzegovina, killed at least 35 people Monday and jeopardized a renewed U.S.-sponsored initiative to bring peace to the Balkans.

The Bosnian government said Bosnian Serb gunmen fired half a dozen shells onto downtown streets crowded with civilians doing their late-morning shopping. More than 80 people were wounded in the deadliest bombardment of Sarajevo in more than 18 months.

The Bosnian Serbs denied responsibility and blamed the Muslim-led but secular government, which they accused of trying to derail the revival of peace talks.

The United Nations said it was still trying to figure out who fired the shells but said the single 120-millimeter mortar that did most of Monday’s horrific damage was fired from the southern ring of the city, which is dominated by rebel Serb positions.

Placing the blame squarely on the Bosnian Serbs, the State Department denounced the attack as a “crime against humanity.” U.S. officials hinted at retaliatory artillery strikes.

Reports from Sarajevo portrayed a gruesome scene: Pools of blood and limbless bodies lined the sidewalks outside a central market as passing motorists hauled away the desperately wounded. The streets had been crowded on a sunny Monday after a weekend of rain. Many of the dead and maimed were children and the elderly.

The attack came as a U.S. negotiating team, led by Assistant Secretary of State Richard Holbrooke, prepared to meet with Bosnian President Alija Izetbegovic in Paris on the first day of a renewed drive to end the war in Bosnia. Izetbegovic delayed the meeting after learning of the shelling, but it was scheduled to take place late Monday night.

Bosnian Prime Minister Haris Silajdzic called for the United Nations and the North Atlantic Treaty Organization, which have pledged to protect “safe areas” such as Sarajevo, to punish the gunmen with air strikes. He urged a suspension of the peace talks.

“Is Sarajevo a safe zone or a killing ghetto?” Silajdzic asked reporters following an emergency meeting of his government. “I don’t think we can continue with a peace process while our people are getting butchered and killed.”

As the United Nations investigated Monday’s attack, questions arose about why either side would want to detract from the Holbrooke mission.

Neither the Sarajevo government nor the Bosnian Serbs are especially happy with the plan that Holbrooke is pushing. It gives the nationalist Serbs nearly half of Bosnia, including the eastern flank, where two Muslim enclaves still exist. But it does not give them as much land as they would like, and it includes several harsh threats of NATO retaliation if the Serbs refuse to go along with the plan.

The Bosnian government, for its part, has voiced opposition to the sacrifice of eastern Bosnia and, bolstered by recent battlefield successes, has suggested it would rather fight on now than settle for an unsatisfactory end.

Bosnian Foreign Minister Muhamed Sacirbey said in Paris that if NATO and the United Nations fail to punish the Bosnian Serbs for the shelling, that will cast doubt on their commitments to use military power to enforce agreements made in the Holbrooke plan.

“If we can expect the Serbians to engage in terrorism with impunity, I’m not sure there is any reason to [believe in] peace talks,” he said.

Holbrooke and other U.S. officials said they were determined to press ahead with the diplomatic initiative, which already suffered a major setback Aug. 19 when three key members of the U.S. negotiating team were killed in a road accident en route to Sarajevo.

“What happened today in Sarajevo is an outrage,” Holbrooke said in Paris. But, he added, the shelling “will not stop the peace process, it will only make us redouble our efforts.” The issue of who fired the shells is important not only because of the impact on the peace process but also because it will determine what kind of retaliatory action is taken.

The United Nations may be interested in leaving the answer ambiguous because it routinely shies from forceful action. A spokeswoman at U.N. headquarters in Zagreb, Croatia, said U.N. radar failed to trace the origin of the mortar fire that caused most of Monday’s casualties.

In Washington, however, the Clinton Administration pressed its allies to retaliate against the Bosnian Serbs, this time by launching artillery attacks on key Serbian targets in Bosnia.

State Department spokesman Nicholas Burns said at a briefing that the allies were “intensively” discussing “a broad range of options” for prompt retaliation, both in NATO and in the United Nations.

Although Burns declined to provide any details, senior officials said privately that the primary option under discussion was to launch artillery attacks to destroy Bosnian Serb batteries and hit other key targets.

Under the plan, the artillery attacks would be carried out by units of the 12,500-member British-French rapid-reaction force now on duty in Bosnia. The force is equipped with 105-millimeter howitzers and counter-battery radar.

The allies have been pinpointing such targets for weeks in anticipation of retaliatory action. Officials say the reason for considering artillery attacks rather than air strikes is that Bosnia is shrouded in bad weather.

If the plan was carried out, it would mark a major expansion of the role of the rapid-reaction force, which so far has been limited strictly to protecting U.N. peacekeeping forces in Bosnia. “Everybody realizes that they [would be] crossing a line,” said one strategist familiar with the plan.

Administration officials portrayed the allies as favoring some sort of quick retaliation for Monday’s shelling. Burns told reporters that allowing the latest shelling of Sarajevo to go unpunished “is not an option . . . that anyone’s decided upon.” But there were indications Monday that the Europeans were not yet prepared to go along with the plan immediately, despite the pressure from Washington.

Although U.S. officials said there was proof that the shells that hit Sarajevo had been fired by Bosnian Serbs, European strategists insisted there was no clear evidence that the Serbs were to blame.

Monday’s carnage occurred about a block from an open-air market that was the scene on Feb. 5, 1994, of the deadliest single massacre in the 40-month siege of Sarajevo. Sixty-eight people were killed and 200 wounded in that attack, which prompted a NATO ultimatum to both sides to remove their heavy weapons from around Sarajevo or face air strikes. Both the Bosnian Serb and government forces respected the “weapons exclusion zone” for nearly a year, until it collapsed and Serbs resumed routine shelling of the capital.

Artillery duels continued throughout Monday. Shells hit Sarajevo’s principal Kosevo Hospital, where blood-splattered doctors were already overwhelmed by victims from the earlier attack. Two patients were wounded. And Bosnian Serbs claimed that retaliatory mortar fire from Bosnian government positions hit a wedding procession in the Serb-held Sarajevo suburb of Ilidza, killing one person and wounding 50.

Wilkinson reported from Vienna and Pine from Washington.