Counter-terrorism officers are investigating a suspected nail bomb attack outside a mosque in the West Midlands, Sky sources say.
Police were called to Binfield Street in Tipton around 1pm after residents reported hearing a loud bang.
Officers said the explosion is being treated as a terrorist incident and some residents have reported finding nails and other debris in the area.
No-one is thought to have been injured but a cordon was set up in part of the town and several streets have been sealed off.
The blast was believed to have happened on a disused railway line behind the mosque.
It was reported near the Kanz-ul-Iman Muslim Welfare Association Central Jamia Mosque in Binfield Street, local councillors said.
Tipton Green councillor Ian Jones said residents in the area had described hearing a “loud thud”, while councillor Syeda Amina Khatun said she was not aware of any previous attacks on the mosque.
“The explosion has gone off on the disused railway line behind the mosque,” she said.
“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.”
A police statement said: “Police have been called to Binfield Street in Tipton this afternoon following reports of a loud explosion.
“Officers were called at 1.06pm and are currently at the scene. A cordon has been set up and the immediate area has been evacuated.
“Some residents have reported finding debris in the area and finding nails. This is being investigated by counter terrorism detectives and forensic officers at the scene.
“There are no reports of any injuries to anyone at this time.
“An investigation is being led by the West Midlands Counter Terrorism Unit and it is being treated as a terrorist incident. There are some road closures in place around the Binfield Street area.”
Among the road closures are parts of Sedgley Road East, Dudley Port, Jays Avenue, Tudor Court, Park Lane East, Crompton Road and Victoria Road.
Anyone who saw anything suspicious in the area is urged to call police on 101 or the independent charity Crimestoppers, anonymously, on 0800 555 111.
The blast came on the day murdered soldier Lee Rigby was remembered at a private funeral service in Bury, Greater Manchester.
Meanwhile, West Midlands Police are still investigating an explosion which occurred near a mosque in the Caldmore area of Walsall on June 21.
The remains of a home-made explosive device were found on June 22 in an alleyway adjoining the Aisha Mosque and Islamic Centre in Rutter Street, Caldmore.
The earlier incident, in which no-one was injured, forced the overnight evacuation of around 150 people from their homes in the surrounding area.