BEIRUT (AP) — Syrian activists say pro-government forces have reached the outskirts of Palmyra in their push to drive Islamic State militants from the ancient town.

It's the Syrian government forces second such offensive this year.

The activist-run Palmyra Coordination Committee says Syrian forces and their allies from the Lebanese Shiite militant Hezbollah group and Iranian advisers are at the town's western gateway, located about 5 kilometers (3 miles) from the famed Roman ruins.

The activist group also reported there were airstrikes across the town on Tuesday morning. The Britain-based Syrian Observatory for Human Rights and Hezbollah's media outlets also reported the advances.

The government lost control of Palmyra in December, less than one year after it reclaimed the town from IS extremists. Archeologists have decried the damage to Palmyra's priceless ruins.