West Midlands Police said officers in Coventry were called to the Jamiah Masjid and Institute at the junction of Durbar Avenue and Queen Mary’s Road at just after 9pm on Sunday.
There were reports of a fight “involving a large group of men, some armed with knives”, outside the building.
Two people were found at the scene with stab injuries, including a 52-year-old man who died a short time later.
A 56-year-old man was arrested by armed officers near by a short time later, and a 27-year-old was arrested in the early hours of Monday.
Both are being questioned on suspicion of murder.
“We’re supporting the family of the man who has died at what is a truly awful time for them, and our thoughts go out to them,” said Det Supt Shaun Edwards, of West Midlands Police.
“We’ve made some really good early progress in this investigation, but there is still a lot of work to do be done in identifying all of those involved in what happened last night.
“We don’t believe this is linked to any other incidents or disputes either in Coventry or the wider West Midlands and it appears to have been an isolated dispute which has ended in tragedy.”
He added that the force would work “flat out” to bring those responsible to justice.
Officers have been speaking to residents and community leaders to offer reassurance.