West Midlands Fire Service said the mystery substance was sprayed in Pizza Hut, McDonald’s and Tesco in Gornal in the Dudley area

Fifteen people needed treatment after being sprayed by a mystery substance in a string of shops and restaurants.

West Midlands Fire Service said the substance was sprayed in Pizza Hut, McDonald’s and Tesco yesterday evening.

The casualties struggled to breathe after the gaseous substance was sprayed in the businesses by an unidentified man.

Eye witnesses took to social media to warn others to avoid the area, reports Birmingham Live.

On Facebook they said: “Hope no-one is injured and everyone is safe by the Tesco in Gornal.

“Just been past and there are numerous fire engines, police and ambulances. Looks like they have taped it off.”