The storm’s strong winds brought down power lines and flooded streets with at least four people killed by falling trees, including two in the Croatian capital Zagreb – according to police and reports in local media.

In Zagreb today, crews were cleaning debris from the streets as authorities cautioned residents against visiting parks where trees had been uprooted and power lines downed.

A crane was also brought down by the storm in Zagreb, seriously injuring one person who was operating the machinery.

Zagreb mayor Tomislav Tomasevic called the storm that struck late yesterday unprecedented in “terms of both force and damage”.

In neighbouring Slovenia one person was also killed by a falling tree near Lake Bled, while an individual was killed in northern Bosnia’s Brcko by unspecified causes, according to local media reports.

The storm in the Balkans comes as swaths of Europe have sweltered in a heat wave trailed by wildfires and health warnings, while stretches of Asia and the US also suffered under extreme weather.