Serbian TV broadcast damage in Belgrade reportedly from NATO air strikes  ALSO: Refugee crisis builds as Serbs reportedly target Kosovars Clinton orders reinforcements to Macedonia Milosevic gets bird's eye view of the new NATO IMAGE GALLERY: NATO strikes Yugoslavia: Day One  MESSAGE BOARD Crisis in Kosovo

March 27, 1999
Web posted at: 9:59 a.m. EST (1459 GMT)

BELGRADE, Yugoslavia (CNN) -- Yugoslavia's capital braced for a fourth day of NATO air strikes, announced to the sound of air raid sirens and a large explosion outside the Belgrade on Saturday afternoon.

Air raid sirens also went off in Podgorica, the capital of Montenegro, the smaller of the two republics that make up the Yugoslav federation.

The leaders of democratic, pro-Western Montenegro have tried to keep the republic neutral, and Montenegrin President Milo Djukanovic has accused his Yugoslav counterpart, President Slobodan Milosevic, of dragging the country into a pointless war with the West.

The new strikes come a day after Belgrade residents watched fireballs shooting into the night sky and shattering windows around the city. Friday's raids were the heaviest and closest to the city's center since airstrikes began Wednesday.

In three days of attacks, Belgrade has become a shadow of its former self. Main streets are largely deserted.

Many in Belgrade took cover Friday in underground shelters. Their fears were compounded by reports that a factory had been hit and was spewing toxic fumes into the air.

Yugoslav authorities said that was the result of a strike on a civilian pharmaceutical plant: NATO said the escaping fumes may have come from a factory that produced missile and rocket fuel. Another NATO strike set fire to a forest close to a popular Belgrade suburb.

NATO resolve 'absolute'

NATO hopes the raids will force Yugoslav President Slobodan Milosevic to sign a peace agreement that will end a year of ethnic strife in the Serb province of Kosovo.

NATO officials say the Yugoslav offensive in Kosovo must stop before the bombing ends.

"NATO's resolve to continue this operation until our objectives are met remains absolute," NATO spokesman Jamie Shea said in Brussels on Saturday.

Yugoslavian media claim the bomb and missile attacks have inflicted numerous -- but unspecified -- casualties. Authorities in Belgrade claim the attacks have created a humanitarian catastrophe with damage to homes, schools, hospitals and infrastructure.

Fuel supplies are restricted to a few priority users such as hospitals and public transportation. City buses and trams are still running, but few people are traveling.

New alert for NATO's Bosnian force

Wreckage from a Yugoslavian MiG-29 shot down after it violated Bosnian air space

NATO forces in Bosnia, meanwhile, were on alert Saturday after reports that two Yugoslav helicopters were approaching the border Saturday.

The helicopters turned back without incident, but not before triggering air raid sirens at the NATO base at Tuzla, a spokesman for NATO's Stabilization Force in Bosnia said.

Saturday's alert at Tuzla came after NATO fighters shot down two Yugoslav jet fighters that crossed into Bosnia on Friday evening. The pilots of those planes were unaccounted for early Saturday, said U.S. Army Maj. Tom Evans, an SFOR spokesman.

"We are working with local police to attempt to find the pilots," Evans said.

NATO boss: Yugoslav troops next

Marines head to protective bunkers in Bosnia after the approach of two Serb helicopters triggered air raid sirens

The forays into Bosnia come as reports mounted that the Serbian-led military has intensified assaults against Kosovar Albanian guerrillas and civilians.

The military alliance said Saturday's air attacks were aimed at crippling the Yugoslav army's capability to wage war on the ethnic Albanian majority in Kosovo.

U.S. Gen. Wesley Clark, NATO's supreme commander, said Friday that new NATO attacks would focus on Serb troops.

Clark said the current campaign was "systematically and progressively" wearing down Yugoslavia's military capability and that troop columns could be hit next. But Clark said NATO air power alone could not stop the Yugoslav army and Serb paramilitaries from carrying out attacks in Kosovo.

NATO member Britain warned Saturday that Milosevic was not only defying peace demands by the international community, but was increasing "indiscriminate killing and burning" in Kosovo.

Note: Pages will open in a new browser window

External sites are not endorsed by CNN Interactive.