Armed men killed three Lebanese soldiers near the Syria border overnight, an official said Tuesday, in the deadliest such attack since the start of the Syrian revolt more than two years ago.

"Three soldiers were killed by armed men while they were in a four-wheel drive vehicle east of Arsal," the security official told AFP, referring to a town in northeastern Lebanon where most residents support the Syrian uprising.

No army spokesman was available for comment and there were no more details immediately available.

Since the start of the rebellion in Syria against President Bashar al-Assad's regime more than two years ago there have been outbreaks of deadly violence on the Lebanese border.

Lebanon is sharply divided over the war in Syria and violence and the majority Sunni Muslim village of Arsal is a particular flashpoint as refugees from the uprising and fighters hostile to the Assad regime traverse the border.

Three mortar shells fired from Syria on Monday killed at least one woman near the eastern Lebanese town of Hermel, a bastion of the Hezbollah movement, a security official told AFP.

Since the start of the Syria conflict in March 2011, a number of rockets and mortar shells have struck Lebanese territory.

On two occasions, the rebel Free Syrian Army claimed responsibility for the attacks in response to Hezbollah's involvement in their fight to oust the Assad regime.