The Yugoslav government ordered its armed forces into the southern province of Kosovo today following two days of serious nationalist disturbances by ethnic Albanians.

Federal officials said it was the "worst outbreak of separatist demands" in the province, which is roughly half the size of Maryland with a population of 1.7 million. Ethnic Albanians, who are overwhelmingly Moslem, make up three-quarters of Kosovo's inhabitants.

The unrest poses the first serious challenge to the successors of Marshal Tito, who died 11 months ago. Officials here said they were determined to suppress Albanian separatist demands since they would amount to the first step in dismembering this complex multinational state.

Tanks and troops were deployed after the government proclaimed a state of emergency in the region, which is adjacent to Albania, following clashes in which two demonstrators were killed and scores of people injured, including a number of police officers.

The demonstrators are said to have chanted slogans demanding the unification of Kosovo with Albania, a militantly isolationist nation that considers itself the one true communist country in the world.

A Yugoslav government statement charged that the riots had been organized by groups outside Yugoslavia "to create instability and endanger the territorial integrity of Yugoslavia."

Eyewitnesses reported that yesterday, the second successive day of rioting, cars and trucks were overturned and burned in the center of the provincial capital of Pristina. The Army guarded public buildings and factories, and ambulances toured the streets to pick up the injured.

Under the emergency measures, a dusk-to-dawn curfew has been imposed, all public gatherings have been banned, and movement into and out of the province has been restricted. Several foreign correspondents visiting the area have been ordered to leave after being confined last night to their hotel and prevented from using the telephone.

Pristina was reported quiet but extremely tense today as most people kept off the streets, which were patrolled by Army and police. But officials fear fresh disturbances Saturday during the funeral of the two demonstrators.

The unrest began among students at the University of Pristina last month and was sparked by complaints over poor food in the university's cafeteria. Since then other groups reportedly have joined in the protests, including miners from the region.

Officials said the security services had been given strict orders not to fire on demonstrators, but to use only tear gas and clubs to break up all illegal gatherings. Fresh security units have been sent into the region.

The rioting has triggered considerable fears among Kosovo's Serbian minority, which is frightened of being the target of the Albanian protests. Several Serbian villages in the province, which is Yugoslavia's poorest region, have erected blockades to protect themselves from possible attack.

Yugoslav officials said it was impossible to say whether the unrest was being stirred up from neighboring Albania, which, in public, has shown great restraint in reporting the clashes. The demonstrators are said to have chanted slogans of "Long Live Enver Hoxha," the name of the Albanian leader.