Firefighters raced to the scene in the city of Liberec on Sunday afternoon where 18 adults and children had been sheltering under a tree when the lightning struck.

One horrified witness told local media: “It happened right next to us, I've never experienced anything so bad.

“We were standing not far from them, and it was really ugly. In the chaos, we all tried to run away.”

Another said: “There were injured people lying on the ground, there were many firemen and ambulances.

“Whoever was hit. We saw how they had to resuscitate the lady there.”

According to emergency services, seven of those hit were seriously injured with five of them having to be resuscitated.

Local media reported that seven adults and eight children had to be taken to the city’s hospital; two were transported to a hospital in the nearby town of Jablonec nad Nisou; and one child was airlifted to a hospital in the capital Prague.

A fire brigade spokesperson said: “Professional firefighters from the Liberec station and volunteer firefighters from Vratislavice in Liberec went to the scene.

“After arriving at the scene of the incident, they conducted a survey where there were a total of 18 people injured in connection with electric shock.

“This is the final sum of today's misfortune on Children's Day in Liberec Vratislavice, where lightning struck.”