Two small bombs hit a Hezbollah convoy in the Bekaa valley, a stronghold of the Shia militant group in eastern Lebanon, on Friday, causing no casualties and only limited damage, a security source said.
The twin bombs were detonated at 5:30 am (0230 GMT) as the convoy of four vehicles passed through the town of Zahle, the source said.
"After the explosion, which caused no casualties, armed men left the vehicles and shot into the air, before continuing on the road to Shtura," the source told AFP on condition of anonymity.
An AFP photographer reported only minor damage to the central reservation.
On 10 June, a bomb targeted two vehicles headed to the Syrian border that were also reportedly carrying Hezbollah supporters.
Sectarian tensions have soared in Lebanon as the 27-month conflict in neighbouring Syria has escalated.
Hezbollah's confirmation at the end of April that its fighters had intervened alongside troops loyal to President Bashar al-Assad sparked resentment among Lebanese Sunnis sympathetic to the mainly Sunni rebels.