Syrian troops backed by Russian warplanes on Thursday advanced into the ancient city of Palmyra, which has been under jihadist control for nearly a year, a monitor and a military source said.
"Regime forces have entered the Hayy al-Gharf neighbourhood in the southwest of Palmyra. They are advancing very slowly because of mines planted by IS (the Islamic State group)," Syrian Observatory for Human Rights director Rami Abdel Rahman told AFP.
"The regime is also advancing from the north of the city," Abdel Rahman said.
A military source confirmed the advance.
"The army has entered from the northwest after seizing control of part of the Valley of the Tombs," he told AFP.
"The clashes, which are ongoing, are fierce."