"Police were called at 10.45 p.m. on Thursday, May 9, to reports that a man, believed to be in possession of a firearm, had entered a mosque on High Road in Seven Kings," Met Police told the Daily Star. "The man was ushered outside the building by those inside. A gunshot was then heard."
The mosque is located in London's eastern Ilford district. Police say they'll keep a large presence in the area overnight.
Tensions are high surrounding Muslims places of worship, amid a wave of mass shootings and attacks on mosques in recent months. Mass shootings in Poway, California, and Christchurch, New Zealand, have left dozens of worshipers dead and millions terrorized.