Russian Muslims Cross Line to Fight in Georgia Enclave : Abkhazia: Yeltsin denounces defiant volunteer soldiers, promises to seal porous border.

Ethnic bloodshed in Georgia threatened to destabilize Russia on Wednesday as scores of Muslim volunteers from southern Russia defied Moscow by sneaking over the mountainous border to help their brethren in the breakaway Georgian region of Abkhazia.

Vowing to resort to terrorism if necessary to secure Abkhazia’s independence, a group calling itself the Confederation of Mountain Peoples urged Muslim volunteers from Russia’s Caucasus Mountains to join the fight against Georgian forces.

Abkhazia, a tiny region along the eastern rim of the Black Sea, declared independence from Eduard A. Shevardnadze’s Georgian government in July, triggering a series of violent clashes that have reportedly killed hundreds on both sides.

Russian President Boris N. Yeltsin denounced the volunteer fighters, who may number as many as 1,200, and warned Russian citizens not to be drawn into “dangerous acts of bravado.” He also promised to seal Russia’s porous border with Georgia, the Interfax news agency reported.

Yeltsin’s angry characterization of the volunteers as “extremists of various hues” seemed certain to further strain Moscow’s relationship with the six semi-autonomous Muslim regions in southern Russia. One region, Chechen-Ingushetia, has already declared independence, although Yeltsin has sworn he will keep his country from disintegrating.

Russian nationals, as well as Jordanian, Turkish and Syrian citizens, reportedly joined the Abkhazian army during fierce fighting Wednesday in Gagra, a resort town on the Black Sea. The Georgian commander in the region reported that his forces had killed 40 Abkhazians and injured 79, but the Abkhazians said only four of their fighters had died and 13 were wounded. Anxious to contain Russian involvement, top Yeltsin advisers had met Tuesday to draw up plans for evacuating Russian citizens from hot spots, although some vacationers have reportedly refused to leave their seaside resorts. Yeltsin is scheduled to meet with Shevardnadze on Sept. 3 in Moscow.

For his part, Shevardnadze again invited Abkhazian separatist leader Vladislav Ardzinba to meet with him for peace negotiations in Tbilisi. Ardzinba did not immediately respond.

“The Abkhazian conflict can grow into a long-term bloody war which will engulf both Georgia and the entire region,” the Georgian State Council said in a press release Wednesday. The group blamed “large numbers of militants” arriving from Russia’s Muslim regions for fanning unrest.

Shevardnadze’s government also faces a strong separatist movement in the Georgian region of South Ossetia, which wants to unite with neighboring North Ossetia across the border in Russia.

The latest escalation in the two-month-old fighting in Abkhazia began this week, when the Georgian military commander there demanded the resignation of the region’s leader, Ardzinba.

He also called for the dissolution of the Abkhazian Parliament, which has clung tenaciously to its independence declaration despite heavy casualties in the Abkhazian army.

Ardzinba rejected the ultimatum and pledged to “defend the country to the bitter end,” Interfax reported.

In response, the local Georgian commander vowed on Russian television Wednesday night to fight until he subdued the region, even if 100,000 Georgians and all 97,000 Abkhazians in the 3,300-square-mile territory were to die.

Ethnic Abkhazians actually make up a minority in the area, which has a population of about 450,000. They are mostly Muslim, while the Georgians were one of the earliest peoples to embrace Christianity.

The Abkhazian secessionist movement has been based in the seaside town of Gudauta since Georgian troops took control of the region’s capital, Sukhumi, in a battle last week that killed at least 50 people.