BEIRUT (Reuters) - A blast which killed one person in Lebanon last week targeted a convoy of cars belonging to the Hezbollah-allied Amal party, parliament speaker and Amal party head Nabih Berri told al Akhbar newspaper.

No group claimed responsibility for the bomb blast on a road near the city of Zahle, in Lebanon's Bekaa Valley on Wednesday which also wounded 11 others.

Berri, a Shi'ite politician, Hezbollah ally and one of most powerful men in the country, said the explosion targeted Amal vehicles heading to an event in south Lebanon commemorating former Amal party leader Musa Sadr, who disappeared in Libya in 1978.

"The explosion was a message to us, it was intended to obstruct the arrival of those from the Bekaa to the movement's event in Tyre," Berri told the Lebanese newspaper.

Amal party sources told the paper that they do not know who carried out the attack, but it was clear who the target was.

Since the eruption of the five-year-old war in neighboring Syria, where the powerful Lebanese Shi'ite Muslim group Hezbollah is fighting in support of President Bashar al-Assad against Sunni Muslim rebel groups, Sunni militants have repeatedly struck in Lebanon.

The spillover has included a number of attacks on Shi'ite areas, among the biggest of which was a bomb attack in the southern suburbs of Beirut in November last year.

(Reporting by Lisa Barrington; Editing by Dominic Evans)