A powerful thunderstorm battered the Venice Film Festival on Thursday, forcing actors and filmmakers to flee the red carpet as lashing rain drenched the Lido.

The blast of bad weather ended days of relentless heat in Venice, which has bathed the world's oldest film festival in blazing sunshine.

The rain disrupted the arrivals for the premiere of the documentary "Russians at War" and then sent the staff and crew of the Georgian film "April" running for cover, leaving the Lido's famous red carpet covered in puddles.

Staff holding umbrellas aloft ushered attendees into the main cinema complex, while the festival's artistic director, Alberto Barbera, smiled apologetically and brushed the rain off the clothes of his soaking guests.