Rebels broke through Russian lines in two major towns in separatist Chechnya today and were locked in battle with government troops, according to reports from the region quoting military sources.

The Interfax news agency, quoting the Russian forces' press center in eastern Chechnya, said 300 fighters had surrounded the military command headquarters and the railway station in Argun, nine miles east of the Chechen capital, Grozny.

A military statement said elite troops were defending both points.

The RIA news agency, quoting military sources, said about 100 rebels had burst through Russian lines farther south, in Shali, and seized the town's main administrative building. It said both Russian troops and local officials had suffered casualties.

Argun and Shali had been under the control of Russian forces, which began their ground offensive in Chechnya in September. Russian troops swept through the northern part of the breakaway region with little resistance but are now engaged in a fierce battle for Grozny and the southern mountains.

Meanwhile, Moscow has told the European Union it was willing to negotiate the Chechen issue--but only with those who accept the territory's future as part of Russia.

Finnish Prime Minister Paavo Lipponen said Russia's acting president, Vladimir Putin, had responded to the EU's criticism of the Chechen war. "He clarifies that the final solution of the crisis can be political and the Russian government is ready to negotiate with anyone who accepts the federation's integrity," Lipponen said.

Putin also said the United Nations, the European Union and the International Committee of the Red Cross would be allowed into Chechnya to help civilians weathering the conflict, but supplies would have to be delivered by the Russians.

CAPTION: Russian soldiers carry a wounded comrade from the outskirts of Grozny. Their push to take the Chechen capital has met with strong resistance.