Syrian state television said government forces fought their way into Palmyra on Thursday as the army backed by Russian air cover sought to recapture the historic city from Islamic State (IS) insurgents.
A monitoring group said the fighting was still outside the city, after a rapid advance the day before brought the army and its allies right up to its outskirts.
The Syrian army earlier this month launched a concerted offensive to retake Palmyra, which the ultra-hardline Islamist militants seized in May 2015, to open a road to the mostly IS-held eastern province of Deir al-Zor.
The state-run news channel Ikhbariya broadcast images from just outside Palmyra and said government fighters had taken over a hotel district in the west. A soldier interviewed by Ikhbariya said the army and its allies would press forward beyond Palmyra.
"We say to those gunmen, we are advancing to Palmyra, and to what's beyond Palmyra, and God willing to Raqqa, the center of the Daesh gangs," he said, referring to Islamic State's de facto capital in northern Syria.
The state news agency SANA showed warplanes flying overhead, helicopters firing missiles, and soldiers and armored vehicles approaching the city.
Civilians began fleeing after Islamic State fighters told them via loudspeakers to leave the centre as fighting drew closer, the Britain-based Syrian Observatory for Human Rights said. The Observatory monitors the war using a network of sources on the ground.
Islamic State has blown up ancient temples and tombs since capturing Palmyra in what the UN cultural agency UNESCO has called a war crime. The city, located at a crossroads in central Syria, is surrounded mostly by desert.
The capture of Palmrya and further eastward advances into Deir al-Zor would mark the most significant Syrian government gain against IS since the start of Russia's military intervention last September.
With Russia's help, Damascus has already taken back some ground from IS, notably east of Aleppo, Syria's biggest city and commercial hub before the war.