ATHENS, July 11 (Xinhua) -- At least six people were killed and dozens injured since gale-force winds hit northern Greece late on Wednesday, said authorities.

According to police, the deaths were caused by three separate incidents, and tourists from the Czech Republic, Romania and Russia were among those killed.

Two Czech nationals died when strong winds blew their travel caravan away in Halkidiki, a popular tourist peninsula in northern Greece that was hit hardest by the storms, said police.

Elsewhere in the region, a man and a boy both from Russia were killed by a falling tree near a hotel in Potidea, and two Romanians died after a restaurant roof collapsed in Nea Plagia.

Dozens of people were injured by the heavy storms and taken to hospital, according to the Fire Service.