Syrian government forces, backed by Russian airpower, Friday made further advances into the Islamic State-controlled city of Palmyra, a day after entering the ancient city, Syrian state media and activists reported.
The forces are coming closer to areas where Palmyra's world-renowned ruins are located, the pro-opposition Syrian Observatory for Human Rights said.
The regime forces are engaged in "fierce" fighting against Islamic State insurgents, according to the Britain-based watchdog.
Two car bombings occurred in an area of hotels on the outskirts of Palmyra as part of militants' counter-attack against the government forces, the Observatory said. No specific casualties were reported.
The state Syrian news agency SANA, citing an unnamed military official, reported that government troops recaptured the strategic Syriatel Hill located near the Palmyra Castle.
"Army units combed the hill after having destroyed the last hideouts of the terrorist organization and dismantled the explosive devices left behind by its members," the official said said.
A Syrian source close to the govenrment meanwhile confirmed that tanks and soldiers were approaching the ruins area in Palmyra, claiming that the militants have fled the site.
The source, speaking on condition of anonymity, said government forces had cut off a major supply line for Islamic State from Palmyra and the town of al-Qarayatain located south-west of the historic city.
Palmyra, a UNESCO World Heritage site, is strategically located in a region between the capital Damascus and the eastern province of Deir al-Zour, mostly controlled by the Islamic State militant group.
Palmyra's fall would be the regime's biggest victory since Russia began an air campaign in Syria in support of President Bashar al-Assad in September.
Islamic State seized Palmyra in Homs province in May, raising global fears about the fate of the city's artefacts.
Since the radical group's takeover of Palmyra, it destroyed several famous sites in the city, including the more than 2,000-year-old Baalshamin Temple.
It also carried out executions in the city's Roman amphitheatre, according to activists.