ISIS executes Syrian soldiers in ancient Palmyra amphitheater
ISIS executes Syrian soldiers in ancient Palmyra amphitheaterScreenshot

Syrian pro-government forces advanced to the edge of the famed ancient city of Palmyra on Wednesday, eyeing a major symbolic victory over the Islamic State (ISIS) jihadist group, a monitor said.

"The regime forces are now two kilometers (a little more than a mile) away on the south side and five kilometers (three miles) away on the west side," Syrian Observatory for Human Rights director Rami Abdel Rahman told AFP.

ISIS seized the city dubbed the "Pearl of the Desert" in May last year, sending shock waves around the world as the group demolished some of the most treasured monuments of its UNESCO-listed World Heritage Site.

Regime forces launched an offensive to retake the city at the start of the month backed by heavy Russian air strikes.

ISIS has fiercely resisted the advance, killing at least 26 pro-government fighters on Monday alone, the Observatory said.

Aamaq, an ISIS-linked website, claimed that 30 troops were killed in an attack by a jihadist suicide bomber.

The recapture of Palmyra would be a strategic as well as symbolic prize for the regime.

Whoever controls the oasis city also controls the surrounding desert - an area of some 30,000 square kilometers (12,000 square miles) extending to the Iraqi border.

That would cut ISIS's area of control from some 40% of Syrian territory to 30%, according to the Observatory.

Global concern for Palmyra's magnificent ancient ruins spiked in September 2015, when satellite images confirmed that ISIS had demolished the famed Temple of Bel as part of its campaign to destroy pre-Islamic monuments it considers idolatrous.

The jihadists have waged a sustained campaign of destruction against heritage sites in areas ISIS controls in Syria and Iraq and in mid-August last year beheaded Palmyra's 82-year-old former antiquities chief.

AFP contributed to this report.