Syrian government forces have advanced into Palmyra with heavy support from air strikes and artillery, state media and a monitoring group say, taking control of several districts in a major assault against Islamic State fighters.
Television footage on Saturday showed waves of explosions inside Palmyra and smoke rising from buildings, as tanks and armoured vehicles fired from the outskirts.
The Syrian Observatory for Human Rights said it was the heaviest assault in a three-week campaign by the Syrian army and allied militia fighters to recapture the desert city and open up the road to Islamic State strongholds further east.
Observatory director Rami Abdulrahman said Syrian soldiers and allied militias had taken control of one-third of Palmyra, mainly in the west and north, including part of the ancient city and its Roman-era ruins. Soldiers were also fighting on a southern front, he said.
Syrian media and Arab television channels broadcasting from the slopes of Palmyra's medieval citadel, one of the last areas of high ground seized by the army on Friday, said troops had advanced inside Palmyra and had taken several neighbourhoods.
The recapture of Palmyra, which the Islamist group seized in May 2015, would mark the biggest reversal for Islamic State in Syria since Russia's intervention turned the tide of the five-year conflict in President Bashar al-Assad's favour.
The group, and al-Qaeda's Syrian branch the Nusra Front, is excluded from a month-long cessation of hostilities that has brought a lull in fighting between the government and rebels battling Assad in western Syria.
Russia, which along with the US had pushed for the talks to take place, has reduced its military presence in Syria but has strongly supported the Palmyra offensive, carrying out dozens of air strikes this week and acknowledging that a Russian special forces officer was killed in combat near the city.
In August, Islamic State fighters dynamited two ancient buildings, the temples of Bel and Baal Shamin, which had stood as cultural landmarks in Palmyra for nearly two millennia. The United Nations described their destruction as a war crime.
Antiquities chief Maamoun Abdelkarim said on Saturday Syria would try to restore the temples, as well as funeral towers and a triumphal arch which were also blown up last year.
“We will rebuild them with the stones that remain, and with the remaining columns,” he told Reuters in Damascus.
Saturday's assault on Palmyra came a day after the US said it had killed several senior leaders including Abd ar-Rahman al-Qaduli, described as Islamic State's top finance official.