PRISTINA, Yugoslavia (CNN) -- The killing of a prominent ethnic Albanian journalist in the Yugoslav province of Kosovo drew condemnation Tuesday as diplomats worried the slaying could make it harder to head off a wider war.

Enver Maloku led the Kosovo Information Center, which disseminates the views of separatist leader Ibrahim Rugova. Maloku was killed by unidentified gunmen Monday in Pristina, the capital of Kosovo.

"The assassination of Maloku is an attack on Albanian freedom of speech," Rugova said Tuesday.

Rugova, a pacifist ethnic Albanian leader, has been at odds with the rebel Kosovo Liberation Army, which has triggered a crisis by capturing eight Yugoslav soldiers.

Maloku's killing and the troops' detention are the latest challenges to the intermittent cease-fire in Kosovo, where KLA guerrillas are fighting for the Albanian-majority province's independence from Serbia, the dominant republic in Yugoslavia.

Milosovic demands release of captured soldiers

More than 1,000 people have been killed in the nearly year- old conflict. And Yugoslav President Slobodan Milosevic warned Monday of a new crackdown in the province unless the KLA released the soldiers it captured Friday.

The KLA wants to exchange the men for ethnic Albanians imprisoned by Yugoslav authorities. But Milosevic, through an official of the Organization for Security and Cooperation in Europe, warned that "time was short" for the release of his troops.

Yugoslav tanks are stationed near the town of Stari Trg, where the soldiers are being held. The government has not commented on the KLA's demands.

Knut Vollebaek, the current OSCE chairman and Norway's foreign minister, also said Maloku's killing was a tragedy that showed how important the international monitoring effort in Kosovo was.

Vollebaek

'Extremists on both sides'

"Extremists on both sides want to hamper us," he said. "We have to work harder and quicker."

One of Vollbaek's deputies, William Walker, said talks regarding the soldiers' release are still going on and could yield a breakthrough Tuesday or Wednesday.

As tensions between Serb and ethnic Albanian communities rise, Serbs are increasingly unhappy with Belgrade's handling of the crisis. Hundreds of them gathered in Kosovo on Monday to protest what they said was their abandonment by the authorities in Belgrade.

The protest, which organizers had decided to hold indoors to avoid any incidents, passed peacefully despite Maloku's assassination and grenade attacks on Serb and ethnic Albanian cafes last week.

Sealing of border urged

Meanwhile, a former international monitor in Bosnia urged NATO to seal off the border between Yugoslavia and Albania, where KLA units operate with impunity.

Former Swedish Prime Minister Carl Bildt said NATO could hardly demand a military pullback by Belgrade if KLA fighters were crossing the Albanian border.

Unless NATO raised the military stakes to give itself more leverage, the alliance could find itself celebrating its 50th anniversary in April "facing their first failure to deter war in a generation," Bildt wrote in the London-based Financial Times.

"The reluctance of NATO to deploy forces in northern Albania has impaired efforts to work towards a settlement," he said.

"NATO has made clear that it is ready to use its air power against Serbia. But it has little leverage over Kosovo's ethnic Albanian separatists. This seriously undermines the possibility of political progress," he said.

The Associated Press and Reuters contributed to this report.