Syrian government forces have entered the ancient town of Palmyra seized by Islamic State (IS) militants last year, state TV has said.
However, observers have said the main fighting is still outside the city, a Unesco World Heritage site.
Officials launched an offensive to retake the city earlier this month, backed by Russian air strikes. The city is situated in a strategically important area between Damascus and the contested eastern city of Deir al-Zour. IS seized the ruins of Palmyra and the adjoining modern town in May. It subsequently destroyed two 2,000-year-old temples, an arch and funerary towers, provoking global outrage.
The jihadist group, which has also demolished several world-renowned pre-Islamic sites in neighbouring Iraq, believes that such structures are idolatrous.
Unesco, the UN’s cultural agency, has condemned the destruction as a war crime. State media showed warplanes flying overhead, helicopters firing missiles, and soldiers and armoured vehicles approaching Palmyra. It said government fighters had taken over a hotel in the west of the city. There has been no independent confirmation of the reports.
The UK-based monitoring group, the Syrian Observatory for Human Rights, said civilians began fleeing after IS warned them via loudspeakers to leave the city centre as fighting was drawing closer, Reuters news agency reported.
The advance comes after the Syrian army and allied militia took control of several hills overlooking the city earlier this week.
Recapturing Palmyra would be a significant victory for the government and Russia, which withdrew most of its forces last week after a six-month air campaign against opponents of President Bashar al-Assad that turned the tide of the five-year civil war in his favour. Despite the reported setbacks, IS claimed its fighters inflicted heavy casualties on the advancing forces, according to its weekly publication Al Naba.
On Wednesday, the group issued pictures purported to show several Syrian army vehicles destroyed by its fire. However, its daily radio news bulletins have not mentioned the fighting in Palmyra in the last few days.
The Syrian offensive comes as representatives of the government and the main opposition umbrella group attend UN-led talks in Geneva aimed at finding a political solution to end the war. The talks have been boosted by a nationwide cessation of hostilities brokered by the US and Russia that has largely held since it began on 27 February.
IS and its rival jihadist group, al-Nusra Front, are excluded from the truce. The reduction in violence has also allowed aid to be delivered to besieged areas. Meanwhile, the US-led coalition said it had conducted eight strikes against IS positions in Syria on Wednesday. The offensive near four cities – Hawl, Manbij, Mara and Palmyra – hit seven of the group’s fighting positions and three tactical units, the Combined Joint Task Force said in a statement.