The Russian military said its warplanes bombed guerrilla positions inside Chechnya along its border with Dagestan last night and early today as Moscow dispatched fresh armor and troops to the region.

The targets of the bombings are Chechen rebels, who recently have made incursions into Dagestan and battled Russian troops there in a bid to establish an independent Islamic republic. The attacks are also apparently retaliation for the four apartment bombings that have killed nearly 300 Russians during the past two weeks. Russian officials have blamed the blasts on the Chechen rebels, who have denied responsibility.

The rebels currently hold no positions in Dagestan, but Russian military officials said they are bracing for the third major offensive since hostilities began in early August. Rather than send in troops, Russian commanders have decided to try to pound the guerrillas from the air, and they said nearly 100 bombing runs were planned for today.

Russian military officials announced they were sending two battalions of flame-throwing tanks and 200 trained snipers to Dagestan. Hundreds of soldiers are being dispatched to the combat zone, in part to set up a cordon along the border with Chechnya, and in part out of anticipation of a fresh guerrilla offensive. Few details of the bombing runs were available today.

On another front, reports from Chechnya said that Russian troops had crossed the border from the neighboring region of Ingushetia, marched more than a mile into Chechnya and started to dig in. However, Ingushetian President Ruslan Aushev denied the troop movement took place, and Russian officials had no comment.

Russian commanders reported today that 243 troops have been killed, 866 wounded and 15 are missing in 6 1/2 weeks of combat in Dagestan. However, two members of the State Duma, the lower house of parliament said Friday upon returning from the war zone that the official reports of Russian casualties have been understated while the number of Chechens killed has been exaggerated.

"Because of the heavy [Russian] losses, corpses are no longer transferred through the Makhachkala airport," said Yuri Shchekochikhin, a member of the parliament's Yabloko faction, referring to the regional capital. "They do that in the more remote places so that people will not know how many of our guys are killed in this war."

Meanwhile, Boris Berezovsky, the Russian tycoon who has long had close ties with the Chechen leadership and negotiated numerous hostage releases from Chechnya, said in a radio interview that Chechen President Aslan Maskhadov has lost control of the region.

Chechnya has sunk into violence, poverty and a cycle of kidnappings since its two-year war for independence from Russia ended in a stalemate in 1996. In the end, Russian troops were forcibly ejected from the region, but a decision on its status was put off for five years by the cease-fire agreement.

"Maskhadov is basically in a desperate situation," Berezovsky said. "He has no power in Chechnya, unfortunately." Berezovsky called for negotiations "with people who are really in control of the situation in Chechnya, and not with those who have no power." He did not identify whom he was talking about.