A man is in a critical condition after being attacked with a knife at a mosque in Bradford.
Emergency services were called to the Islamic Centre on Newton Street in Bradford at around 10am on Monday.
A man in his 20s was found with serious injuries and taken to hospital for treatment.
A man was arrested from a nearby address and is currently in police custody. West Yorkshire Police said it is not seeking anyone else.
It comes as people gathered at the mosque for the end of Ramadan and the celebration of Eid al-Fitr.
One witness, Cllr Taj Salam (Lab), said: "It's a very big day today for us after 30-days of fasting and the mood has been dampened by this incident."Very shocked. There must have been 120 people in the hall at the time of the attack."
The matter is not being treated as a hate or terrorist related incident at this time
Chief Superintendent Rob McCoubrey of Bradford Police, said: “This is clearly a distressing incident for the victim’s family and local community and West Yorkshire Police will continue to provide visible reassurance and support as the investigation progresses. "