Athens, Jul 11 (IANS): Six tourists were killed and 30 others injured in a violent freak storm that swept across a region of northern Greece, the media reported on Friday.

Gale-force winds, heavy rain and hailstorms lashed Halkidiki, near the city of Thessaloniki, late on Wednesday, the BBC reported.

A Czech couple died when their caravan was blown away, and two Romanians and two Russians were also killed.

A state of emergency was declared and more than 100 rescue workers deployed.

Charalambos Steriadis, head of civil protection in northern Greece, described it as an "unprecedented phenomenon".

The storm followed a spell of very hot weather in Greece with temperatures soaring to 37 degrees Celsius over the past two days.

Images and video posted on social media show trees toppled, cars overturned and buildings damaged.

Emily Kishtoo, from Surrey, was at a beach party with her family when the storm hit on Wednesday night.

"It literally came out of nowhere," she told the BBC.

"The lights cut out on the beach that we were in - it was chaos. People running, screaming and just trying to basically get off the beach."