The Syrian army and Lebanese Hezbollah fighters said on Sunday they had entered the rebel-held city of Zabadani on the second day of a major offensive to capture the border area around the Beirut-Damascus highway.
The army, backed by Hezbollah, has long sought to wrest control of Zabadani, near the Lebanese border, from the rebels who have held it since 2012, a year after the start of the Syrian civil war.
The Lebanese Shi'ite group Hezbollah's al Manar television station said its fighters and the Syrian army had entered the Jamaiyat district in the western part of Zabadani, about 45 km (30 miles) northwest of the capital Damascus.
Footage showed ground troops entering parts of the city lying in a lush agricultural plain adjoining Lebanese eastern mountain range that includes the Qalamoun area.
The offensive began on Saturday and was preceded by several days of aerial and artillery bombing of outposts held by a coalition of mainly Sunni Muslim jihadist fighters defending the city.
The Syrian army also said on state television their fighters had seized the Sultani district, east of the city, while Hezbollah said it had encircled the northern portion.
Earlier the Syrian army said: "Tens of terrorists were killed and injured" in the assault.
The Syrian army, aided by Hezbollah, last March captured the western mountains overlooking Zabadani but rebels who control the eastern hilltops have used rocket launchers to hit army and Hezbollah posts.
Over 2,000 rebels from groups that include al Qaeda's Syrian offshoot Nusra Front have planted mines and fortified their positions inside the besieged city ahead of expected heavy street fighting, rebels contacted by phone said.
"God willing, our spirits are high they won't enter the city unless we are all martyrs or we have killed them," said Abdullah Anas, a fighter from the hardline Islamist group Ahrar al Sham.
The latest offensive is part of Syrian President Bashar al-Assad's effort to shore up his control over western Syria.
The capture of the city would secure a safe arms and troops corridor for Hezbollah, whose military role inside Syria has been growing steadily since the start of the conflict.
The area around the once popular resort city was part of a major supply route for weapons sent by Syria to Hezbollah before the 2011 outbreak of the Syrian conflict, which has killed more than 200,000 people.
The Syrian army is fighting on several other fronts. As well as battling rebels around the southern city of Deraa and the northern city of Aleppo, it has been fighting Islamic State as the militant group attempts to seize government-held areas of the northeastern city of Hasaka.