The Lebanese army reopened a road between two towns near the Syrian border on Wednesday to try to calm sectarian rivalry aggravated by the conflict in neighboring Syria, Reuters reported.
Shi'ite Muslims from the Bekaa Valley town of al-Labwa, where Hezbollah has strong support, had erected sandbag barriers at the weekend to cut off the Sunni Muslim town of Arsal from the rest of Lebanon.
The blockade followed days of rocket attacks on al-Labwa which residents blame on Syrian Sunni rebels who have fled across the border to Arsal after a Syrian military offensive.
Arsal hosts tens of thousands of Syrian refugees.
The Lebanese army said in a statement that it was increasing its presence in the area, and the mayor of al-Labwa told Reuters the road was reopened at around 6 a.m. (0400 GMT). "Traffic is back to normal," said Ramez Amhaz.
The border area has been steadily sucked into Syria's three-year-old conflict as Syrian President Bashar al-Assad's forces attack nearby rebel bases and suspected Syrian rebels fire rockets at Shi'ite towns to punish Hezbollah for backing Assad.
Sunni demonstrators blocked roads in Beirut, the Bekaa Valley and near the southern city of Sidon on Tuesday in protest at the road closure affecting Arsal. A Reuters photographer said a bystander was shot dead during a protest in a Sunni district of Beirut. The source of the gunfire was not immediately clear.
Tensions have been especially high in and around Arsal after Syrian forces and Hezbollah gunmen recaptured the border town of Yabroud from rebels on Sunday, sending a stream of refugees and fighters across the border into Arsal. Hours later, a suicide car bomber attacked a local Hezbollah stronghold.