Syrian and allied forces, backed by Russian air strikes, entered the Islamic State group-held town of al-Qaryatain on Sunday, having gradually surrounded it over the past few days, state media and a monitoring group said.
Al-Qaryatain is 100 km (60 miles) west of Palmyra, which government forces recaptured from Islamic State last Sunday.
The town has been held by Islamic State group since late August.
Syrian state media said government forces entered the town from a number of directions.
The Syrian Observatory for Human Rights said fighting continued between Islamic State group and government forces in the town, which is surrounded by mountains.
"Practically speaking, the town can be said to have fallen militarily, because the regime controls the surrounding hills," the Observatory's director Rami Abdurrahman told Reuters.
The Observatory said that more than 40 air strikes from Russian and Syrian planes hit near the town on Sunday.