The attacks took place in the Wadi Khaled region, where both Syrian armed rebels and civilians have taken refuge from the violence at home.

There have recently been clashes between armed men on the Lebanese side and the Syrian military.

There are fears the Syrian conflict will spread to neighbouring countries.

'Panic and fear'

The first artillery shells from across the border landed on farm buildings early on Saturday, killing one woman, local residents say.

Two more people were killed in the second strike just hours later.

Children are believed to be among the injured, with the Lebanese National News agency reporting that local residents were fleeing their villages "in a state of panic and fear ".

It was not immediately clear whether the victims were Lebanese or Syrian nationals and whether the buildings were hit deliberately or caught in crossfire during a battle between the Syrian army and opposition fighters, the BBC's Richard Colebourn in Beirut reports.

The border area has become increasingly volatile in recent weeks, and fears are now growing that Lebanon could be sucked into the 16-month Syrian conflict.

Like Syria's other neighbours - Turkey, Iraq and Jordan - Lebanon has absorbed thousands of refugees fleeing from the violence.