Elite Hezbollah fighters poured across the border from Lebanon into Syria today, a watchdog and others said, bolstering regime forces battling to retake the key rebel stronghold of Qusayr.
Washington expressed concern about Hezbollah's role and diplomats said the EU was poised to place the powerful Shiite militant group's military wing on its list of international terrorist groups.
Separately, Israeli and Syrian forces traded fire on the Golan Heights. The Syrian army claimed it had destroyed an Israeli military vehicle that crossed the armistice line but the Jewish state denied that.
In central Homs province, Hezbollah fighters were reportedly leading the battle for Qusayr, three days after the Syrian regime began an assault to regain control of the town.
"It's clear Hezbollah is leading the assault," Syrian Observatory for Human Rights director Rami Abdel Rahman told AFP, adding that regime air strikes were ongoing and "much of the town is now destroyed."
A source close to Hezbollah told AFP it "has sent new elite troops to Qusayr".
Hezbollah's television channel broadcast images of funerals for five members it said were killed carrying out their "jihadist duty".
The Observatory said more than 100 people have been killed in Qusayr since the fighting began on Sunday, including 31 Hezbollah fighters, 70 rebels and nine soldiers.
Abdel Rahman described the rebel response to the assault in Qusayr as "fierce," but expressed concern for the fate of some 25,000 trapped civilians.
Pro-regime daily Al-Watan said loyalists had taken control of all Qusayr's official buildings and "raised the Syrian flag" above them.
The town, which lies between Damascus and the coast, and sits between the Syrian city of Homs and the Lebanese city of Tripoli, is a key strategic prize.
The regime is hoping to protect its access to the coast and deprive the rebels of links to Tripoli, a majority Sunni town that provides a conduit for fighters and weapons.
"It is important for the Syrians, the Iranians and Hezbollah to control the road" linking Tripoli to Syria, Lebanese analyst Waddah Sharara told AFP.
Tripoli is also home to a minority of Alawites, an offshoot of Shiite Islam to which Assad belongs. Violence there between the sects has broken out regularly since the Syrian conflict began in March 2011.
Today, a security source confirmed the death of Sunni man from the town in clashes.
