Zugdidi, Georgia ? Russian tanks roared deep into Georgia on Monday, launching a new western front in the conflict, and Russian planes staged air raids that sent people screaming and fleeing for cover in some towns.

The escalating warfare brought sharp words from President Bush, who pressed Moscow to accept an immediate cease-fire and pull its troops out to avert a “dramatic and brutal escalation” of violence in the former Soviet republic.

Russian forces for the first time moved well outside the two restive, pro-Russian provinces claimed by Georgia that lie at the heart of the dispute. An Associated Press reporter saw Russian troops in control of government buildings in this town just miles from the frontier and Russian troops were reported in nearby Senaki.

Mikheil Saakashvili, Georgia’s president, said his country had been sliced in half with the capture of a critical highway crossroads near the central city of Gori, and Russian warplanes launched new air raids across the country.

The Russian Defense Ministry, through news agencies, denied it had captured Gori and also denied any intentions to advance on the Georgian capital of Tbilisi.

The western assault expanded the days-old war beyond the central breakaway region of South Ossetia, where a crackdown by Georgia last week drew a military response from Russia.