Top, NATO says 70 percent of the Serb army's oil supplies have been destroyed. Bottom, damage in Baric, a suburb of Belgrade RELATED VIDEO Yugoslav officials continue to say the exodus of refugees is being caused by NATO's aggression, not Belgrade's army. CNN's Alessio Vinci is there. (April 19) Real 28K 80K Windows Media 28K 80K The call for ground troops is increasing, as CNN's Chris Black reports (April 18) Real 28K 80K Windows Media 28K 80K 'The funeral of NATO': CNN's Jonathan Karl takes a look at the price the alliance may pay (April 18) Real 28K 80K Windows Media 28K 80K To view the latest video streams on the strikes in Yugoslavia, use the arrow buttons below to scroll through the video gallery.        Windows Media Real        28 K 80 K IMAGE GALLERY: The Kosovo refugees Protesting the NATO strikes Devastation of the Kosovo capital The Serbs and Kosovo  ALSO Two Americans identified as victims in fatal Albania crash Camps fill as refugees seek shelter Clinton, Yeltsin to confer on Yugo war  MESSAGE BOARD Crisis in Kosovo  MAPS NATO officials describe the air campaign

April 19, 1999
Web posted at: 2:14 p.m. EDT (1814 GMT)

In this story: Other cities targeted Britain's Robertson: NATO winning Reports of mass graves disputed RELATED STORIES, SITES

BELGRADE, Yugoslavia (CNN) -- Four large explosions rocked the Belgrade suburb of Baric before dawn Monday, as NATO airstrikes continued to target petroleum refineries and chemical plants.

NATO also reported what appeared to be renewed fighting by the Yugoslav Army in the western and northern parts of Kosovo against the Kosovo Liberation Army.

NATO military spokesman Brig. Gen. Giuseppe Marani said that Yugoslav forces had increased helicopter and fixed-wing flights in Kosovo, but were unable to carry out any large operations because of their vulnerability to NATO aircraft.

NATO spokesman Jamie Shea said that Yugoslav troops were now being used to channel refugees into the Kosovo capital from the northern parts of the province.

"We have increasing reports that forces are creating an anti-humanitarian corridor from the north to Pristina, funneling 150,000 refugees so that at Pristina they can be put on trains and sent south to Macedonia," he said. "This suggests that this is not random, but is being done on an almost scientific and systematic basis."

Bad weather slowed NATO's attacks, Marani said, including delaying the arrival of 24 Apache helicopters to Albania. NATO was not expected to move the helicopters to Albania until after Monday.

Other cities targeted

Serbian television reported one of Monday's NATO targets was a chemical factory producing polyvinyl materials. Serbian authorities warned of an environmental catastrophe if NATO hit a separate chemical complex, which they have lit up at night to prevent an attack.

Shea said 70 percent of the Yugoslav Army's petroleum supplies had been destroyed, but said NATO is "aware" that some fuel supplies are reaching Yugoslavia through Bulgaria and Macedonia and was planning action to cut those off "within the scope of our current operations."

"We do know from the reports that we receive that the Yugoslav army is hurting now because of a lack of oil, both of supplies and the ability to distribute it," said Shea.

Other NATO bombs hit the regional government buildings in downtown Novi Sad, Yugoslavia's second-largest city.

Serb TV also reported aerial attacks on other sites previously attacked -- Kraljevo in central Serbia, Subotica near the Hungarian border and the Kosovo capital of Pristina.

In addition, Belgrade Radio said NATO planes attacked Paracin in central Serbia, Sremska Mitrovica, northwest of Belgrade, and Obrenovac, another Belgrade suburb.

Britain's Robertson: NATO winning

Earlier Monday, British Defense Secretary George Robertson vowed the bombing would continue because NATO is "stamping out evil at the heart of Europe."

"NATO's air campaign in succeeding in weakening (Yugoslav President Slobodan) Milosevic's repressive capability, and we are exacting a heavy price for his ethnic cleansing activity," Robertson said. "NATO's resolution remains unshakable."

Robertson said if he were Yugoslavia's defense minister, he would be "a very worried man."

"He would be getting a cold feeling down his spine," said Robertson. "As defense minister he will know the real truth that he is hiding from people. And he will know that in a month NATO has only lost one plane, and he will despair at the freedom that NATO aircraft roam the skies destroying his military at will, during the day as well as at night."

NATO says these aerial photos show evidence of mass graves in Izbica

Reports of mass graves disputed

Reports from NATO that aerial observations had turned up evidence of mass graves sites in Kosovo were challenged Monday by a Yugoslav farmer who said the pictures showed his field after he had been working the soil.

"They are ruining us with their lies," the unidentified man said on Serb television. "There are no mass graves here, no one killed here. CNN is full of lies."

NATO officials had said they had evidence of 43 mass grave sites, and said that Serbs were forcing ethnic Albanians to work on "grave-digging chain gangs." Photos showed at the NATO news briefing were from sites at Pusto Selo and Izbica.

Earlier, Yugoslav Deputy Prime Minister Vuk Draskovic said he knew nothing about the graves and did not believe what was being said about the photographs.

Correspondents Alessio Vinci and Ben Wedeman contributed to this report.

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