Syrian government forces have advanced into the Eastern Ghouta region, the opposition's main stronghold on the outskirts of Damascus, a war monitoring group reported on Monday.
The Syrian Observatory for Human Rights (SOHR) said there was intense fighting between fighters loyal to President Bashar al-Assad and militants from the Islamist insurgent group of Legion of Mercy in the town of Ain Tarma and its surroundings, reports Efe news.
In Ain Tarma, government troops marched through the area of Wadi Ain Tarma, where they had taken control of a warehouse and four buildings.
During the clashes, at least three rebels were killed and 12 others injured, the UK-based group said, adding there were an undetermined number of casualties among the pro-government fighters.
For three days, the government forces have been trying to advance toward Ain Tarma in an attempt to impose a siege on neighbouring Jobar district on the northeastern outskirts of Damascus.
The offensive coincides with a ceasefire brokered by the US and Russia in the provinces of Daraa, Sweida and Quneitra in southwestern Syria.