A military bomb disposal team has been called to a mosque in Wolverhampton and the surrounding area evacuated after police received a warning of "possible device activation".
West Midlands Police cleared Wolverhampton Central Mosque at around 8pm Thursday to ensure "the absolute safety and security" of the community.
The operation came after information was unearthed in the investigation into the recent attacks at nearby mosques in Walsall and Tipton.
Two men, both Eastern European, were on Thursday arrested under the Terrorism Act in connection with the explosions.
Searches and checks were set to continue overnight, police said.