BEIRUT - Syrian government forces launched a long-planned offensive early Sunday on the strategic city of Qusair and neighboring rebel-controlled villages near the Lebanese border, with heavy shelling that began shortly after midnight, according to opposition and pro-regime accounts.
The attack may be a prelude to a larger ground offensive by Syrian army units and Hezbollah fighters coming from neighboring Lebanon, where the Shia militant group is based.
There was no confirmation Sunday from Hezbollah that its militiamen were involved in the battle to retake Qusair, which has been in rebel hands for more than a year.
Pro-government media reports said President Bashar Assad's troops had entered the town in Homs province, long a rebel stronghold.
Accounts of the fighting in Syria are difficult to verify independently because the government restricts access by international journalists, and the United Nations pulled out its observers last year.
Qusair, just a few miles from Syria's border with Lebanon, is of strategic significance to both sides in Syria's war. It is along the corridor used by rebels to smuggle weapons and fighters into the city of Homs, Syria's third-largest, while the government seeks to maintain an open road from Homs south to the capital, Damascus.
Qusair once had a population of about 40,000 but most residents have fled. It has been the site of fierce clashes between opposition and government forces.
The new offensive comes after a string of government victories that have pushed back rebel forces in Homs province, one of the most contested zones in the conflict, and elsewhere in Syria.