(CBS) U.S. troops faced off against angry Kosovar protesters in a Wednesday scuffle that didn’t last long, but may have been inevitable, reports CBS News Correspondent Allen Pizzey.

American soldiers, who were hailed as liberators by ethnic Albanians when they rolled into Kosovo barely two months ago, are trying to keep the peace even-handedly. That has often put them at loggerheads with The KLA and its supporters, who have been accused of attempting to ethnically cleanse Serb civilians left in the province.

U.N. officials estimate that that as few as five percent of the pre-war Serb population remains in the provincial capital, Pristina.

"Many of those who remain are the mostly vulnerable of the pre-war population," said U.N. High Commission for Refugees spokesman Ron Redmond.

"They are the elderly, they are disabled and a lot of them are isolated. It is highly unlikely that these people were involved in the persecution of Albanians, but that doesn't seem to matter to the thugs who are now terrorizing," Redmond said.

Aid workers must now deliver food to Serbs too frightened to leave their homes, and even that requires a NATO escort. Any security gap gives the ethnic Albanians a chance to pay Serbs back in kind for what was done to them during the war.

Those carrying out the revenge attacks enjoy wide popular support. "Let ur soldiers go," chanted the crowd confronting U.S. troops Wednesday.

After the scuffle, in which a few people were injured, the detained KLA soldiers were released and cheered as heroes. By then, the U.S. troops trying to make Kosovo safe for everyone had apparently become yesterday's heroes.

Meanwhile, Russian soldiers attached to the Kosovo peacekeeping force (KFOR) have endured more than scuffles. Officials of KFOR reported that a Russian soldier on guard duty was shot in the shoulder on Thursday by a sniper. On Wednesday, a Russian tank was attacked by a mob of angry ethnic Albanians.

Moscow is a key ally of Yugoslavia, and ethnic Albanians accuse Russian peacekeepers of favoring Serbs.

But Russians are not the only peacekeepers in the crosshairs. British peacekeepers came under fire Thursday while patrolling an area where Serbs had been threatened and told to leave.

Seven ethnic Albanians were detained following a shootout and a car chase in a Serb area just north of Pristina, said British Lt. Col. Robin Hodges. Two of the seven were wounded by British fire.