A Mexican restaurant at Cheshire Oaks was evacuated after a suspected arson attack.
The blaze was started in the ground floor toilet of Chiquito on Coliseum Way in Ellesmere Port .
Emergency services were called to the scene at 1.45pm on Friday (September 30).
Police believe the fire was started deliberately.
Customers had to be escorted out of the restaurant, but nobody was harmed.
A Cheshire Fire and Rescue Service spokeswoman said: "Fire engines were sent to Chiquito on Coliseum Way and found a fire in a ground floor toilet.
"The crews, four firefighters wearing breathing apparatus, put out the fire using a hose reel jet.
"A thermal imaging camera was used to check there were no further areas of heat and a high pressure fan used to ventilate the building.
"It is thought the fire was started deliberately and a joint investigation with Cheshire Police is being carried out."
Anyone with any information is urged to contact Crimestoppers, anonymously, on 0800 555 111 or Cheshire Police on 101.