Syrian troops fought rebels on Saturday in a bid to take back a key supply route linking the centre of the country to Aleppo in the north, a monitoring group said.
"Fierce battles raged pitting troops against rebels. Regime troops fought to reopen the road linking Hama to Aleppo," Syrian Observatory for Human Rights director Rami Abdel Rahman told AFP.
Rebels cut off the so-called Desert Road on Thursday. The army had been using it as its main supply route to Aleppo province, large swathes of which are under insurgent control.
In March the army's command had announced "the return of safety and security" to villages located along the road.
The road leads to Aleppo international airport, scene of heavy fighting pitting rebels against troops for several weeks.
Rebels launched in February a bid to take over airports and air bases in Aleppo province in a bid to take out the air force's capacity to deploy.
Signup to our newsletter and follow us on Facebook and Twitter!
With large parts of the province out of army hands, the rebels' main obstacle in the north is the regime's air force.
In central Syria, meanwhile, fierce battles raged in Qusayr in the province of Homs, with rebels fighting troops, pro-regime militia and members of the Lebanese Shiite movement Hezbollah, which supports the Damascus regime.
The town, under rebel hands for more than a year, was pounded Saturday using rockets and tank fire, said the Observatory.
Further south, seven army troops were killed in a rebel raid on a checkpoint in the town of Abel, added the Observatory.
At least 22 people were killed across Syria on Saturday, according to a preliminary toll by the Britain-based watchdog, which relies on a broad network of activists, doctors and lawyers for its reports.
At least 95 people were killed in Syria on Friday, it said.