Syrian government forces say they have seized the last major town held by rebels in western Latakia province.
State TV said Rabia, in rebel hands for four years, was overrun by the army and "popular defence" forces.
The province is a stronghold of the Alawite community to which President Bashar al-Assad belongs.
Russian forces played a key role in the recapture of Rabia, according to the UK-based monitoring group, the Syrian Observatory for Human Rights.
The head of the Syrian Observatory, Rami Abdel Rahman, told AFP that President Assad's forces had surrounded the town from three sides in the space of 48 hours by capturing several villages.
Russian air strikes played "an essential role", he said.
On its website, the group, which relies on monitors to supply information from the ground, said regime forces backed by Russian officers and Hezbollah militants subsequently took control of the villages of Daroshan and al-Rawda.
The Syrian Observatory speaks of violent clashes between Syrian forces and al-Nusra Front fighters.
Rabia had been controlled by different groups including al-Nusra - an al-Qaeda affiliate.
Latest government success: Sebastian Usher, Middle East analyst, BBC World Service
If confirmed, the recapture of Rabia would be the latest success in the government's campaign to reassert full control of the Alawite stronghold of Latakia.
Essential to the army's progress has been the support of Russian air strikes.
The government's recent victories should limit the rebels' ability to shell the provincial capital, also called Latakia. Last year saw a number of such shellings, which brought the war dangerously close to one of the very few cities in Syria that has been largely untouched - physically at least - by the war.
It may also give Mr Assad's forces a chance to challenge rebel control of the neighbouring province, Idlib.
This all comes as there is increasing doubt as to whether preliminary peace talks will start this week as scheduled. One of the key sticking points remains over which rebels are invited. Syria and other parties to the conflict are under pressure to accept a wider and more representative number of groups.
According to the Syrian Observatory, the capture of Rabia poses a greater threat to rebel supply lines from the north and could see pro-government forces advance to the Turkish border.
The town's fall comes amid a concerted fightback by the Syrian military, including the recapture of the village of Salma on 12 January.