"The security forces, who had been encircling Tall Kalakh since the morning, fired machine guns. At least three people were killed and several were wounded," the witness said.
A hospital source in Lebanon said that a man, Ali Basha, who was admitted to hospital earlier Saturday after fleeing from Syria with gunshot wounds had died of his injuries.
The deaths came a day after thousands of people took to the streets following the main weekly Muslim prayers for anti-regime protests in the town, which lies about 160 kilometres (100 miles) north of Damascus.
Hundreds of Syrians, most of them women and children, fled across the border from Tall Kalakh for Lebanon on Saturday, an AFP correspondent and a local official said. Some of them had gunshot wounds.
"More than 500 people have crossed since 7:00 am (0400 GMT), most of them women and children," said Mahmud Khazaal, a town councillor.
At least five people who entered the area of Wadi Khaled in northern Lebanon on Saturday had been shot and an AFP correspondent said he saw two women and a man rushed away by ambulance to Lebanese hospitals.
Khazaal said intermittent gunfire could be heard across the border in Syria, and that refugees fleeing the violence reported security forces were "shooting and besieging Tall Kalakh."
Fleeing violence in their hometowns, hundreds of Syrians have since last week crossed into Wadi Khaled by foot from villages near the border, bringing with them mattresses and other basic provisions.
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