A 25-year-old man from Rugeley has been arrested after a bomb threat was made against Birmingham Central Mosque on Facebook.
West Midlands Police said they received a number of calls from concerned members of the public in relation to the threat on Sunday night.
A thorough search of the mosque was carried out by officers and specialist search dogs trained to search for explosives. Nothing out of the ordinary was found in the building, police said.
A West Midlands Police spokesman said: "At around 5:15am today (Monday) a warrant was executed at an address in Rugeley, Staffordshire and a 25-year-old man was arrested. He remains in custody this afternoon where he continues to help police with their enquiries."
Detective Inspector Nigel Harrison, who is leading the investigation, added: "We are grateful to the mosque for their cooperation with this ongoing enquiry and I would like to reassure the community that we are taking this incident extremely seriously."