The Syrian army has taken a several hills southwest of the former rebel stronghold of Yabrud as they seek to secure territory between there and the Lebanese border, a security source said Tuesday.

On Sunday, backed by fighters from Lebanon’s Shiite Hezbollah and local militia, they seized Yabrud after a month of shelling and air strikes.

They are now moving to secure the area along the nearby border with Lebanon, which has been a key supply route for the opposition, allowing them to transport fighters and weapons.