PARIS, April 15: At least 75 people were killed and 25 injured when two convoys of refugees were bombed during NATO air raids in western Kosovo last night even as the United States, while expressing regret over the civilian casualties, said bombing of Serbian targets would continue.Sixty-four people were killed and 20 injured, including three Serb police escorts in Meja village, Serbian officials had claimed late on Wednesday, adding later that in a separate attack earlier on Zrze village, six people were killed and 11 injured.``In a murderous attack last evening, two separate refugee convoys were bombed, most of them made up of women, children and elderly ethnic Albanians who were being escorted by Serbian police toward the border,'' a Yugoslavian official statement carried by the Serb media centre said.``NATO bombs created a new humanitarian catastrophe and tragedy. The bodies are literally littered on the highway and the strike is nothing but crime against humanity,'' a Yugoslavian foreignministry official said.US Defence Secretary William Cohen told a Senate committee in Washington that NATO bombing of Yugoslavia would continue to intensify.Expressing ``regrets'' for what happened yesterday,'' Cohen was swift in saying that he considered it ``grotesque'' for Yugoslav President Slobodan Milosevic to be accusing NATO of ``atrocities,''NATO officials, who initially ducked for cover as Yugoslavian authorities reported the carnage, later admitted that 64 Kosovo refugees were killed.``Preliminary investigations showed a bomb dropped from an alliance aircraft appeared to have mistakenly hit the convoy. Serb police or military vehicles may have been in or around the convoy,'' NATO said in a official statement issued from Brussels.NATO said it could not confirm Yugoslav figures but added the alliance ``regrets any harm to innocent civilians and reminds that the circumstances in which the accident occurred are wholly the responsibility of President (Slobodan) Milosevic and hispolicies.''Earlier in the day, NATO vehemently denied responsibility saying it was the Serb aircraft which killed the 64 civilians. The tone of denial changed during the course of the day as more evidence pointed towards NATO strikes against the convoy. The six killings in Zrze have not been confirmed so far.NATO officials said General Wesley Clark, leading the allied attack, would leave for the NATO air base in Vicenza, Italy, to investigate into the incident which has caused considerable embarrassment to the alliance which was boasting of ``precision attacks'' for the last three weeks against Yugoslav military targets.``NATO pilots attacked only military vehicles. The aircraft immediately returned as they realised there were civilian vehicles on the road. I don't know yet to what degree we may have caused collateral damage. We are continuing to investigate,'' NATO spokesman Jamie Shea told reporters at Brussels.Earlier in London, the deputy chief of Britain's defence staff expressed his ``deepregret'' if NATO warplanes were responsible for the reported deaths of 75 refugees in western Kosovo.And British Foreign Secretary Robin Cook accused Yugoslav leaders of hypocrisy.``I will not accept the criticism that is emanating from Belgrade,'' Cook said in a press conference. ``How dare they now produce crocodile tears for people killed in the conflict for which they are responsible.''Experts say that frustrated by Yugoslavian resilience in withstanding NATO air strikes, the alliance's planes are now firing missiles despite cloud cover and bad weather. As a result, the pilots are not able to distinguish between civilian and military targets resulting in civilian casualties.Meanwhile, European Union leaders backed a United Nations peace initiative calling for an suspension of air raids if Belgrade acted immediately to halt the violence in Kosovo, withdraw all its forces, allow an international security force to deploy in the province and permit refugees to return home.UN Secretary-GeneralKofi Annan met EU leaders and NATO chief Javier Solana in Brussels last night to discuss the new proposals brought forward by Germany.