An explosion near a mosque that police are treating as a terrorist incident is believed to have been an attempt to cause "serious harm".
Counter-terrorism officers launched an investigation after residents heard a loud bang in Tipton, West Midlands, before nails and other debris were found.
The blast on a disused railway line at the rear of the mosque caused minor damage, thought to have been caused by a nail, to the window of one property. No one was reported to have been hurt.
Army experts were still clearing the area to make sure it was safe, but residents would be allowed back into their homes as soon as possible.
Assistant Chief Constable Gareth Cann said the inquiry was launched after a loud bang was heard by residents. "As a result of that our officers attended and arrived very quickly at the scene," he said.
"From what the officers were told they started to make a search of the area and because they'd been told about the large bang - people had also reported seeing some smoke - the officers started to discover some debris, including nails, which seemed to have been scattered over a fairly wide area.
"As a result of that they started to evacuate people from the immediate area to make sure that they were safe. Since then the officers have called in a number of specialist resources, including colleagues from the Army bomb disposal teams and other specialist investigators."
Officers were called to Binfield Street just after 1.06pm, on the same day murdered soldier Lee Rigby was remembered at a private funeral service in Bury, Greater Manchester. Tipton Green councillor Ian Jones said residents in the area described hearing a "loud thud".
Councillor Syeda Amina Khatun added: "The explosion has gone off on the disused railway line behind the mosque. There are lots of police around so there must be want for them to be here. The whole estate has been blocked off. People are surprised that something like this has happened."
The loud bang was reported near the Kanz-ul-Iman Muslim Welfare Association Central Jamia Mosque in Binfield Street, said the councillors.