A Syrian rebel unit has claimed responsibility in a video for killing four Shi'ite men in Lebanon this week as Syria's civil war spills into its smaller, religiously divided neighbour.
In the video, posted on Tuesday by a group calling itself the "Syrian Mujahideen Unit", a fighter says his brigade killed the four men as they were trying to enter Syria.
He said they were members of Hezbollah, the Lebanese Shi'ite militant group that has actively helped Syrian President Bashar al-Assad in his fight against a mostly Sunni Muslim revolt.
Another video posted by the same group showed the four men's identification cards as well as two assault rifles and two pistols the Syrian rebels say they found on the men.
The civil war in Syria has inflamed tensions in Lebanon's Bekaa Valley near the border, where Sunnis who support the Syrian rebels live close to Shi'ites who back Assad.
Rockets fired from areas believed to be controlled by Syrian rebels have targeted the Shi'ite town of Hermel in the past, while a Syrian helicopter has crossed into Lebanon and fired at buildings in Sunni border areas.
Some Lebanese Sunnis have gone to fight alongside rebels in Syria, where anti-Assad protests erupted in March 2011 and met a violent response. An armed conflict then developed in which the United Nations says 93,000 people have been killed and 1.6 million refugees have fled to neighbouring countries.