Syrian government forces backed by Lebanon's Hezbollah terror group on Sunday entered Zabadani, the last rebel-held town in the Qalamun region on the Lebanese border, state media said.
The advance was also confirmed by the Syrian Observatory for Human Rights monitor, and reported by Hezbollah's Al-Manar television station.
"Heroic army forces in cooperation with the Lebanese resistance took control of the Al-Jamaiyat neighborhood in western Zabadani and the Al-Sultana neighborhood in the east of the city," state television said in a breaking news alert.
"Operations are continuing with dozens of terrorists killed and wounded," it added.
The Britain-based Observatory confirmed that regime forces and Hezbollah had entered the city, adding that army helicopters had dropped at least 12 barrel bombs on the town since Sunday morning.
It said at least 14 regime forces and Hezbollah fighters had been killed in fighting for the town over the past 24 hours, along with at least 11 rebels.
Hezbollah's Al-Manar television aired what it said was footage of its fighters and Syrian soldiers entering the town.
Zabadani is around 20 kilometers (12 miles) north of the capital and was one of the first towns to fall into rebel hands in early 2012.
It is the last major opposition position in the Qalamun region, which runs along the border with Lebanon and was once a bastion for the rebels.
In late 2013, government forces and Hezbollah began a major campaign to take back the region, culminating in April 2014 with the capture of the ancient Christian town of Maalula.
Zabadani has remained a lone holdout in the region, and has been under regime siege for more than a year.
Syrian state media announced an official beginning to the government's operation to retake the town on Saturday.
Hezbollah is a key ally of the Syrian government and has sent fighters to bolster its forces against an uprising that began in March 2011.