Police, paramedics and fire crews were scrambled to a major alert at the Texaco service station at Old Trafford after a member of staff was blasted with dry powder through a night pay window.

The terrified member of staff thought he’d been covered with a dangerous chemical, but the emergency services later discovered three hooligans has discharged a fire extinguisher through the hatch.

The employee dialled 999 at about 6.50am on Easter Sunday (March 27), fearing he could have been sprayed with a dangerous chemical.

The North West Ambulance Service (NWAS) sent a rapid response vehicle, an ambulance and members of the specially-trained Hazardous Area Response Team (HART), and police and and fire crews were also dispatched.

A North West Ambulance Service spokeswoman said: “We received a call from somebody who had been sprayed with an unknown substance and there was considerable cause for concern. Due to the unknown nature of the substance initially, a large-scale response was required.”

She said the cashier, in his late 20s, had to be cleaned and ‘decontaminated’, and a number of other people at the petrol station also had to be checked over by paramedics. No-one was hurt.

CCTV footage shows how the attackers, dressed in tracksuits and hoodies, approach the kiosk and speak with the lone shop worker through the night service hatch, sending him to collect items for purchase.

But just before they leave, one of the group angles the hose of a dry powder fire extinguisher through the opening and sprays the staff member before the trio make off.

Petrol station manager Hamid Gaurya said: “The member of staff is fine. I phoned him this morning and he said he was OK, but still shaken up by the experience.

“It’s sad to see how some people out there get up to this kind of nonsense for no reason. It wasn’t just the police that were called, it was paramedics and the fire service as well.

“We also had to close for an hour, meaning a loss of business, and there was a lot of cleaning up to do and stock to throw out because it had been ruined. It’s very disappointing.”