The storm toppled and ripped open a Czech family's caravan, killing an elderly couple in their seventies and injuring two others

Thessaloniki (Greece) (AFP) - Six people died and at least 23 were injured as a fierce storm tore through a beachfront in one of Greece’s top tourist areas, terrifying thousands of holidaymakers caught in the open, authorities said Thursday.

Six tourists including two children were killed – two each from the Czech Republic, Russia and Romania – in the northern region of Halkidiki, near Greece’s second city Thessaloniki, in the storms late Wednesday.

There were reports on Thursday that a seventh body had been recovered, but they have not yet been confirmed.

“There was panic, people were howling and running to hide inside,” said Haris Lazaridis, owner of a tavern where a 54-year-old woman from Romania and her son were killed when the roof caved in.

“For five minutes it was hellish,” Lazaridis told AFP. He added that more than 100 people were sheltering under the roof when it collapsed.

Strong winds and hail on Wednesday evening tore into the beach front of Halkidiki region, one of Greece's most popular tourist areas

In an emergency briefing, government spokesman Stelios Petsas on Thursday said the area had been hit by winds of more than 100 kilometres (62 miles) an hour.

Twenty-three people were still receiving treatment in nearby hospitals, including a 72-year-old woman in critical condition, he said.

Most of them are tourists, Petsas said, declining to give nationalities.

The seventh body recovered Thursday is believed to belong to a missing fisherman.

The freak storm only lasted about 20 minutes, according to witnesses, but it was enough to overturn cars, uproot trees and balcony railings and cause mudslides.

Road access to part of Halkidiki was still severed owing to a fallen high-voltage electricity pylon, Petsas said, adding that restoring power to the area could take another two days.

“It was a miracle that there weren’t more deaths,” said 39-year-old Kyriakos Athanasiadis, who is vacationing in the area.

Map locating severe hailstorms in Greece on July 10

“Nearly all the coastal restaurants were full, and you could see large objects flying,” he told AFP.

One woman reportedly told hospital staff she was picked up by the wind and thrown in a garbage bin, which then rolled away.

- ‘Unprecedented phenomenon’ -

On a beach in Sozopoli, the storm toppled and ripped open a Czech family’s caravan, killing an elderly couple in their seventies and injuring their 48-year-old son and 19-year-old grandson.

“The wind picked up the caravan as if it were a matchbox,” said Yiannis Karabourniotis, owner of a nearby tavern.

“You cannot describe it. There used to be 50 pine trees around my establishment. Most were uprooted or snapped in two,” he said.

The storm damaged beach bars in Nea Plagia, in Chalkidiki

Elsewhere in the region, a Russian man and his son were killed by a falling tree.

“It was an unprecedented phenomenon,” said Charalambos Steriadis, head of civil protection in northern Greece.

Officials have declared a state of emergency and army crews were working around the clock to restore electricity.

“I want to express my sorrow on behalf of all… We mourn for the loss of these souls,” said Citizen Protection Minister Michalis Chrisochoidis, who is overseeing operations in the area.

“We are in solidarity with their relatives, with the people who have lost their families,” he added.

At least 140 rescue workers were involved in the operation, emergency chief Vassilis Varthakoyannis said.

Prime Minister Kyriakos Mitsotakis, who took over Sunday after general elections, cancelled his meetings to address the disaster, his office said.

The storms came after temperatures in Greece soared to 37 degrees centigrade (98 degrees Fahrenheit) over the past two days.

The Greek national observatory said it had recorded over 5,000 lightning bolts around the country on Wednesday evening.