Iran-backed Hezbollah has been dealt a blow in Lebanon's parliamentary election with preliminary results showing losses for some of its oldest allies and the Saudi-aligned Lebanese Forces party saying it had gained seats.

With votes still being counted, the final make-up of the 128-member parliament has yet to emerge. The heavily armed Shi'ite Muslim group Hezbollah and its allies won a majority of 71 seats when Lebanon last voted in 2018.

The current election is the first since...