Braving Syrian army patrols and treacherous winter weather, hundreds of people fled into Lebanon in the last 24 hours to escape the heaviest shelling of their border towns in a year-long crackdown on protests against President Bashar al-Assad.
In the hillside town of Arsal in Lebanon's Bekaa Valley, residents say between 100 and 150 families arrived from Syria on Sunday - one of the biggest refugee influxes so far.
A dozen families spent Sunday night in a three-storey apartment block in Arsal after fleeing what they said was a sustained army attack on the Syrian town of Qusair with tanks, rocket-propelled grenades and helicopters.
Families trekked on foot through snow-capped hills to safety, but many others were caught as they tried to flee, one refugee told Reuters in Arsal.
"My house was bombed and a giant hole was left in one side of the house," said a 21-year old man, dressed in a black leather jacket and a black and white kaffiyeh scarf to keep out the freezing mountain air.
He said Syrian tanks entered Qusair on Sunday morning.
"I saw with my own eyes helicopters firing missiles and machine guns," he added. "My entire family fled and spent the day walking here."
Although Arsal is only 10 km (six miles) from the Syrian border, the young man's family had to walk 40 km through valleys, he said, as the mountain route was cut off by snow.
Only a few families, of roughly 2,000 people who fled Qusair, made it across the border without being stopped by Syrian troops.
"When we arrived into Lebanese territory I looked behind me and saw about 40 men being caught by Syrian soldiers who were pursuing us," he said. "We managed to get out, but they were not so lucky."
The man's father, a husky-voiced 60-year-old, has rented a room in Arsal for his family to sleep in for a few dollars a day. "Qusair has been a nightmare. No food, fuel, bread, electricity," he said.
Standing on another terrace at the house, a woman wearing a headscarf and a conservative long grey dress said she fled the Homs suburb of Khalidiya a week ago.
"The Syrian army has completely destroyed Baba Amr. It took me four days to get out of Homs province, but my husband is still trapped there," she shrieked.
Along with her children, the woman managed to get across the Lebanese border at the official crossing, but said it was impossible for men to do the same.
As she spoke, the woman's children played in the thick snow which blankets the mountainous terrain.
Most refugees said they would not return until the Syrian government fell. But one, a rotund middle-aged man, said he was a fighter with the Free Syrian Army who had travelled to Lebanon just to bring his family to safety.
"I came to Lebanon yesterday to bring my children here. I will return to Homs," he said.