Syrian state TV says government forces have entered the historic town of Palmyra, which has been held by Islamic State militants since last May.
The report said fighting around midday on March 24 raged near the archaeological site on the southwestern edge of the town.
Syrian troops have been on the offensive for days in an attempt to capture the town that is home to one of the world's most famous archaeological sites.
Many of Palmyra's Roman-era relics, including the 2,000-year-old Temple of Bel and the iconic Arch of Triumph, have been blown up by IS.
Russia's Defense Ministry said on March 24 that its warplanes have struck targets around Palmyra in support of the Syrian Army's offensive there.
The ministry said Russian warplanes hit 146 targets between March 20 and 23, killing 320 militants.
Last week, Russian President Vladimir Putin ordered a pullout of some Russian warplanes from Syria but said that strikes against IS and the Al-Qaeda-linked Nusra Front will continue.
Those groups have been excluded from a Russian- and U.S.-brokered cease-fire that began on February 27 and has largely held.