Reports of massacres of ethnic Albanian civilians in the embattled province of Kosovo have heightened the likelihood of NATO airstrikes against military targets in Yugoslavia.

Britain has called for an emergency meeting of the U.N. Security Council Thursday to discuss the fighting that has left hundreds dead and forced at least 275,000 to flee.The United States and other leading nations were also meeting Friday in London on Kosovo. Secretary of State Madeleine Albright and Defense Secretary William Cohen planned to brief U.S. senators on the massacres later Thursday in Washington.

On Wednesday, residents of Golubovac said Serb forces surrounded a pocket of refugees last Saturday and singled out at least 13 men to kill. They said the victims were already buried but pointed to saucer-sized pools of dried blood and empty cartridges in front of a fence where they said the refugees were shot.

Farmer Naim Hodzaj said in addition to the executions, Serb police had killed several other men individually, including his 37-year-old brother, Ramadan, who was doused with gasoline and set on fire. His brother's burned body lay on a path on the edge of the woods.

Earlier this week, diplomats, journalists and human rights workers saw as many as 18 mutilated bodies in nearby Obrija, five miles north of Golubovac, including those of women and children.

The mass killings last weekend in the Drenica region, where Serb-led forces are trying to crush ethnic Albanian rebels, are among the most gruesome developments since the offensive began in February. The rebel Kosovo Liberation Army is seeking independence for Kosovo, whose population is mostly ethnic Albanian.

"We rule out any possibility that our members did something like this," Serb police Col. Bozidar Filic said. "In that area, we had clashes with terrorists, and a number of them have been arrested."

There was no way to corroborate the ethnic Albanian accounts. Both sides have been accused of massacres in Kosovo.

Britain and Austria urged an international investigation into what Austrian Foreign Minister Wolfgang Schuessel called the "bestial" massacre at Obrija, which the Serbs call Gornje Obrinje.

"This was not an act of war, it was plain cold murder," British Foreign Secretary Robin Cook said.

The government's Tanjug news agency called Western reports a "media farce" and said the Obrija killing was staged to generate more pressure on Serbia, the main republic in Yugoslavia.

Serb authorities promised earlier this week that troops would retreat to their barracks after claiming victory over the KLA.