SOUTHERN CHECHNYA, Russia (AP) _ The Russian military on Sunday claimed to have made inroads into rebel-controlled territory in southern Chechnya, capturing strategic heights overlooking a key rebel stronghold.

Federal forces also kept up air and artillery bombardments of the Chechen capital Grozny, as a major offensive to take the city entered a second week. Russian commanders said their forces fought off an overnight rebel attack on federal artillery positions northwest of Grozny, on the Tersky Heights.

After days of fighting, Russian paratroopers on Saturday overran the strategic heights near Vedeno, a major rebel center in southern Chechnya, the military said. The Russian forces can now position artillery on the heights, making it easier to drive the rebels out of Vedeno.

Russian artillery also continued to pound the nearby southern village of Serzhen-Yurt.

Russian forces have been trying to crush rebel fighters concentrated in the mountainous south of the republic. Russian jets and combat helicopters flew about 100 combat missions over southern Chechnya during the past 24 hours, the military said Sunday.

After taking the heights, the Russian forces seized a large cache of arms and ammunition, including grenade-launchers, two anti-aircraft rocket-launchers and a number of flame-throwers, said Maj. Alexander Diordiev, a military spokesman.

Chechen officials said many civilians were trapped in southern mountain villages, unable to leave because of the constant shelling of the area. The civilians include Grozny residents who had fled the capital in hopes of escaping to Georgia, which borders Chechnya to the south, but were stuck in the villages of Itum-Kale, 50 miles south of Grozny, and Shatoi, 35 miles south of Grozny.

``People cannot venture out of their homes because the shelling continues around the clock,'' said Ramzan Bisiyev, the administration chief of the village of Rodina just outside Grozny. He was trying to negotiate with Russian authorities for a safe corridor so civilians could leave southern Chechnya for Russian-controlled areas in the north.

``In despair, people go through the forests, along mountain passes, and come under artillery fire. A lot of dead bodies lie around those forests,'' said Bisiyev, who visited southern Chechnya last week.

No figures were available on the number of civilians trapped in the south, but Bisiyev said only about 10 percent of residents had managed to leave the area.