An advance contingent of Russian troops flew into Kosovo today to help reopen a strategic airport and join an uneasy alliance with NATO peacekeepers struggling to rein in widespread ethnic unrest.

As the Russians disembarked, there were more reports of looting in Pristina and ethnic Albanians burning or taking over Serbian homes in the capital city and the western town of Pec. The Pristina homes of Gypsies were burning tonight. Local ethnic Albanians claimed that the Gypsies, who they called collaborators, set fire to their own homes before abandoning them. A potentially explosive confrontation was defused in the northern town of Kosovska Mitrovica when an ethnic Albanian rebel leader stepped in to urge calm.

An Ilyushin-76 jet carrying 21 paratroops and 18 airport technicians touched down at Pristina's airport in early afternoon, the first airplane to land in Kosovo since NATO began its peacekeeping mission two weeks ago. It was followed moments later by a French transport carrying equipment to help make the airport fully operational.

The Russians will join about 200 of their countrymen who seized Slatina Airport on June 12 after traveling overland from Bosnia, beating NATO into Kosovo by hours and forcing tough negotiations on Russia's role in the peacekeeping.

The flag of Russian airborne forces flew atop the terminal building, with a British flag off to one side.

Before the Russian specialists left Chkalovsky airfield near Moscow today, President Boris Yeltsin authorized 3,616 troops as Russia's contribution to the peacekeeping force in Kosovo. In addition to regular forces, these include 210 Interior Ministry and 30 border guard troops being sent to join an international police force.

Gen. Georgi Shpak, commander of the airborne troops, told radio station Echo Moskvy that 70 percent of the Russian contingent will be made up of active duty servicemen. The remaining 30 percent are contract soldiers recruited through military enlistment offices.

"We are expecting colossal difficulties," Shpak said. "In the first place, it's the problem of the relations between us and the Albanians, the peaceful population and those who come down from the mountains carrying arms. But I believe we will use our experience in order to try and do our best to minimize the number of military conflicts."

Russia still has not decided how to pay for the estimated $69 million annual peacekeeping cost, a difficult sum for a military that cannot pay its regular soldiers on time. Apparently to save money, Russia is considering sending the bulk of the peacekeeping force by rail or sea, Defense Minister Igor Sergeyev said.