The door of a mosque in Greater Manchester has been set on fire in a suspected Islamophobic 'retaliatory' arson attack following Monday night's bombing outside a concert venue in the same city, which left at least 22 people dead and dozens more injured, according to statements from the mosque's imam.

Imam of the Jamia Qasmia Zahidia Islamic Centre in Oldham, Mohammad Saddiq, reportedly said that the fire started early Tuesday at around 2 a.m. local time through the door's letterbox, when a passerby witnessed the flames and called the local fire brigade.

No one was inside the building at the time of the fire.

"We have no idea why somebody would target us. We are a religious and educational center. I've been involved here for three years and never dealt with anything like this," Siddiq said.

Investigators were at the scene of the fire Tuesday morning and a police investigation is currently ongoing as they survey CCTV footage.

When questioned whether the attack could have been in response to Monday night's bombing, the imam said that it was a possibility, but that they could not confirm a motive at this time.

"It's sad to see more misery in Manchester. What happened last night was terrible but this is not the way to respond," Siddiq added.