A mosque has said it is "work as normal" as two Ukrainian men continue to be questioned under anti-terror laws following the discovery at the site of an explosion nearby.
Wolverhampton Central Mosque reopened after it was evacuated as the "seat of an explosion" and debris were found on a roundabout across the road late on Thursday.
The find was made following the arrest of two men in Small Heath, Birmingham, in connection with blasts close to mosques in Walsall and Tipton.
The men, aged 25 and 22, are being questioned on suspicion of being involved in the commission, preparation or instigation of an act of terrorism.
Speaking outside the mosque in Wolverhampton on Friday, West Midlands Police Assistant Chief Constable Marcus Beale said they now believed a device exploded on the Fiveways roundabout at around 9.15am on June 28, just after rush hour.
"As a result of intelligence following the arrest of two men in Birmingham yesterday, we have carried out a detailed forensic search of the Wolverhampton scene. We have discovered it was the scene of an explosion that took place on June 28," the officer told reporters.
The device, details of which have not yet been released, is believed to have been planted in the early hours of June 28 or on the previous night.
The force received reports about a "loud bang" and "a puff of smoke" on June 28 and a normal local response officer was sent. However the location of the explosion was not discovered until specialist teams came to investigate on Thursday night, Mr Beale said.
He appealed for anyone who saw anyone acting suspiciously near the roundabout on the night of June 27 or the morning of June 28 to contact the force. No one was injured in the explosion and no damage was caused.
In a statement, Communities Secretary Eric Pickles said: "The calm and measured community response to yesterday's discovery of a very real terrorist threat to worshippers at Wolverhampton Central Mosque showed a city united against hate. The fact that Friday prayers went ahead today with hundreds of worshippers in attendance is proof yet again that those who seek to sow the seeds of division have failed."