(Adds details, background)
BEIRUT, July 11 (Reuters) - At least two rockets were fired on Friday from southern Lebanon into Israel, Lebanon's news agency and security sources said, adding that it was unclear who had fired them.
Southern Lebanon is a stronghold of Hezbollah, a Shi'ite Muslim group that battled Israel seven years ago and is engaged in Syria's civil war in support of President Bashar al-Assad. Palestinian factions are also in the same area.
The news agency NNA, citing its correspondent in Tyre, said the rockets were fired towards "occupied territories" at 6.30 a.m. (0430 GMT) from the Hasbaya area in Lebanon.
Israel responded with military shells, security sources said.
In December, rockets launched from south Lebanon struck northern Israel, provoking a response across a border that had been largely quiet since a war in 2006. (Reporting by Sylvia Westall; Editing by Paul Tait; Editing by Clarence Fernandez)