BEIRUT: Syrian government forces advanced into Palmyra on several fronts on Saturday with support from airstrikes and artillery bombardment, state media and a monitoring group said, and live television showed waves of explosions inside the city.

The Syrian Observatory for Human Rights described it as the heaviest assault yet in a three-week campaign by the Syrian army and allied militia fighters to recapture the desert city from Daesh.

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 parts of its ancient Roman-era ruins. Soldiers were also fighting on a southern front, he said.

State-run television also said the army was advancing inside Palmyra, recapturing several neighborhoods.

Television footage from the slopes of the medieval citadel, which was seized by the army on Friday and overlooks the city, showed tanks and armored vehicles firing into Palmyra.

Waves of explosions hit buildings, and smoke could be seen rising from many locations. Earlier, the Observatory said that Daesh terrorists had launched counter-attacks — including car bombings — against advancing soldiers.

Palmyra's ancient Roman temples and archway, blown up by Daesh last year, will be restored once Syria recaptures the city, said the head of the antiquities authority.

The recapture of Palmyra, which Daesh seized in May 2015, would mark the biggest reversal for the terror group since Russia’s intervention turned the tide of the five-year conflict in President Bashar Assad’s favor.

The group, and Al-Qaeda’s Syrian branch the Nusra Front, is excluded from a month-long cessation of hostilities agreement that has brought a lull in fighting between the government and rebels battling Assad in western Syria.

Palmyra had a population of 50,000 according to a census more than 10 years ago. Those numbers were swelled hugely by an influx of people displaced by Syria’s conflict.