ISIL fighters have re-entered Syria's ancient city of Palmyra from where they were driven out nine months ago, activists say.
The Palmyra Coordination network said ISIL, or the Islamic State of Iraq and the Levant group, had entered Palmyra's northern and northwestern neighbourhoods on Saturday and nearly encircled the city.
The activist-run group, which maintains contacts inside the city, said ISIL, also known as ISIS, was approaching the city's UNESCO Heritage site as well.
The Syrian Observatory for Human Rights (SOHR), a monitoring group, said ISIL fighters had "occupied" the city's northwest, with the armed group engaged in "fighting with the army in the city centre".
A commander from the Jaish al-Mujahideen group, based in the Aleppo countryside, said earlier on Saturday that the ISIL attack was forcing the Syrian government to divert troops from Aleppo.
Recapturing Palmyra could be a major strategic victory for ISIL and open up territory stretching from the Iraqi border to its strongholds of Deir Az-zor and Raqqa.
ISIL captured Palmyra, also known as Tadmur, in May last year and began a campaign of destroying some ancient sites and using others to stage mass executions.
The group also destroyed the infamous Tadmur prison, where thousands of government opponents were reported to have been tortured.
They were driven out of Palmyra in March by Syrian government forces backed by Russian air strikes.
According to defence analysts at think-tank IHS Jane, ISIL lost about 12 percent of its territory in 2016, and about 14 percent in 2015.
|The 2,000-year-old city of Palmyra has been listed as a World Heritage site [AFP]
Source: Al Jazeera and news agencies