NEAR PETROVO, Serbia (Reuters) - The sound of heavy guns could be heard on Tuesday from near Petrovo, one of four Kosovo villages international monitors said had been targeted in a coordinated attack by Yugoslav security forces. A Reuters correspondent near Petrovo, a village next to Racak, where 45 ethnic Albanians were found killed on Friday, heard sporadic firing and several artillery blasts. It was not immediately clear where the firing came from and what it was targeting. "Yugoslav authorities informed us this morning that there would be continued operations around the village of Racak and I think that may well account for what you are hearing now," Sandy Blyth, spokesman for the international monitors in Kosovo, said by telephone. He said the government had not given any details of the operations or said why they were being carried out. Renewed fighting broke out in the area on Sunday after international monitors failed to persuade investigating magistrate Danica Marinkovic to conduct her investigation into the killings without a police escort. The Serb-run media centre said on Tuesday that one policeman had been killed and two wounded around noon in Racak while on patrol securing the site where the bodies were found.