Police in the West Midlands say they are hunting a serial bomber of mosques.
They have linked three attacks across the area in recent weeks.
One of the devices, which exploded close to a mosque in Wolverhampton last month, has only just been found.
From the West Midlands ITV News correspondent Juliet Bremner reports:
Police have confirmed that two Ukrainian men aged 22 and 25 have been arrested in relation to the explosions at mosques in Tipton and Walsall.
They are still being questioned on suspicion of being involved in the commission, preparation or instigation of an act of terrorism.
Police have confirmed they have found evidence of an explosion and debris near a mosque in Wolverhampton.
The debris was found on Fiveways roundabout which has been declared safe. A forensics team will remain at the site today.
Nothing was found at the Wolverhampton central mosque on Waterloo Road which has now been re-opened.
WOLVERHAMPTON: Area around Five Ways island still cordoned off. Enquiries will continue into tomorrow morning.
We would like to thank those affected by tonight's searches and ongoing investigation for their patience, understanding and support.
Police in Wolverhampton have evacuated Wolverhampton Central Mosque and a number of surrounding roads as part of a security alert.
Police said a military bomb disposal team is en route.
West Midlands Police officers have closed a number of roads in Wolverhampton following the evacuation of the city's central mosque.
CLOSED: Gorsebrook Rd @ Stafford Rd, Waterloo Rd @ Oxley St, Stafford Rd @ Cannock Rd, Dunstall Rd @ Staveley Rd, Cannock Rd @ Crown St.
Wolverhampton Central Mosque has been evacuated as part of a security alert into attacks on mosques in the local area. In a statement, police said:
As a result of urgent enquiries underway as part of the investigation into the attacks near mosques in Walsall and Tipton, information has been received regarding a possible device activation on 28 June at Wolverhampton Central Mosque, Waterloo Road, Wolverhampton.
This new information has resulted in an evacuation of the mosque and the surrounding area at around 8 pm this evening (Thursday 18 July). This measure is in place to ensure the absolute safety and security of our communities.
A number of specialist and local police officers are at the scene and a military bomb disposal team is en route.
A number of road closures are in place.
Hayley Firman, head of West Midlands Crown Prosecution Service's Public Protection Unit, said the parents of a 23-month-old boy who died of a heroin overdose had exposed their son "to an unsuitable environment" of "hard drugs."
It is the duty for any responsible parents to protect their children from harm and drugs, but (Simon) Jones and (Emma) Bradburn exposed their young, defenceless son to an unsuitable environment, which contained hard drugs that would ultimately lead to his death.
I would like to take this opportunity to praise my prosecution team who worked very closely with the police to ensure that justice was delivered for Daniel.
This is a tragic case where a young life has so needlessly been lost because of the carelessness of those who should have been there to ensure his safety.
Officers who initially visited the scene reported finding a clean and well maintained house that looked like any ‘normal’ family home - but then upstairs we found a very different story.
The main bedroom was untidy and strewn with drug paraphernalia.
It seems that during his short life, Daniel became accustomed to living amongst these items and, tragically, consumed a quantity of heroin that ultimately led to his death.