New Ethnic War Spreads in U.S.S.R. : Central Asia: Thousands have massed to avenge 48 people killed in violence between the Soviet republics of Kirghizia and Uzbekistan.

Thousands of people armed with spears, stones and guns are massing along the border between the Central Asian republics of Kirghizia and Uzbekistan, seeking to avenge the 48 people who have died in ethnic warfare, a top Soviet official said today.

Interior Minister Vadim Bakatin told lawmakers in Moscow that the violence, which began three days ago in one town in Kirghizia, had spilled over to Uzbekistan and spread to five regions in Kirghizia.

He described the situation as “very complex” and said it could explode into fighting between the two republics.

A state of emergency was declared today in Frunze, the capital of Kirghizia, where one person died from a beating, cars were destroyed and thousands of people surrounded Communist Party and government buildings, an official said.

They demanded the resignation of the republic’s leaders and urged Kirghiz to unite and strike back at Uzbeks, Tass news agency said.

“Kirghiz, unite!” and “Kirghiz to Osh!” they chanted, referring to the frontier town 195 miles to the south, where the fighting flared Monday over a land dispute.

The unrest has been the latest in a series of ethnic outbreaks fueled by poverty or political conflict that have occurred in the more permissive political climate of President Mikhail S. Gorbachev’s five-year tenure.

The conflicts, especially a bitter feud between Armenia and Azerbaijan in the Caucasus, have claimed hundreds of lives and forced tens of thousands of people to flee their homes in the face of attacks by rival ethnic groups.

An estimated 2,000 Uzbeks tried to cross the border from their republic to fight in Osh, but security forces stopped them and sealed all roads between Uzbekistan and Kirghizia, the unofficial Interfax news agency reported.

A state of emergency and curfew are in effect in Osh, with troops patrolling the streets and sealing off the city.

Overnight in Frunze, security forces fired warning shots to disperse groups of students who “committed acts of hooliganism,” damaging a children’s hospital, a cloth factory and a market, Tass reported.

A state of emergency and curfew were declared in Frunze, where more than 4,000 angry students rallied in the center of the city and demanded a chance to fight Uzbeks, said Ivan V. Pavlov, a department head on the city’s party executive committee.

Participants at the rally also gave leaders of the republic three days to resign, Tass said. Militia units held back the crowds.