Counter terrorism officers have been called up after police declared the discovery of a bomb in a mosque in Walsall a "hate crime".
Hundreds of residences were evacuated around the Aisha mosque and Islamic centre, in the Caldmore area of the city, after the small home-made device exploded on Saturday night.
No one was injured and the explosion caused minimal damage.
The remains of the device was taken home by the mosque's imam before anyone realized their significance, reports say.
Assistant Chief Constable of West Midlands police Sharon Rowe said last night: "The force is taking this attack against the mosque very seriously and we have a major investigation under way.
"To that end, I have called in support from all over the force, including the West Midlands Counter Terrorism Unit, which has a number of experts supporting the inquiry.
"Specialist investigators have been working all day and continue to ensure that we maximise every opportunity from the crime scene."
She added: "At this stage we are keeping an open mind on a motive, but have recorded it as a hate crime. A hate crime is any criminal act committed against a person or property that is motivated by the offender's hatred of people because of their gender, race, religion, disability or sexual orientation."
Police have stepped up patrols in Walsall.
Zia Ul-Haq, a committee member and spokesman for the mosque, told BBC WM the device was handed in on Saturday evening, and committee members called police at about 10.15pm because it looked suspicious.
He said: "The package was found along the front boundary wall, on the corner of the building. It was found by one of our worshippers who after midday prayer was going home, and he had a look and it looked suspicious, so he picked it up and took it home.
"He showed it his wife and his wife said, 'Well, it looks like something suspicious so you should take it to the mosque'. So he brought it to the mosque but unfortunately there was nobody responsible in the mosque so he took it back home.
"Then he brought it back in the evening and then our imam had a look at it, and he took it home because nobody thought it was that serious."
Eventually, several people, including members of the committee, got together at the mosque and decided to call police after assessing the item, which was reported to contain a battery.
"I said it looks suspicious and we decided to call the police. As soon as the police came they said we should not have handled it."
Mr Ul-Haq told the BBC that the mosque had been in existence for more than 40 years and had very good relations with communities of all faiths, holding open days for non-Muslims.
The incident follows a spate of similar attacks on mosques and Islamic centres around the country following the murder of British soldier Lee Rigby in southeast London.
Last week two men were charged in relation to an alleged arson attack at a mosque in Gloucester, and an Islamic cultural centre in Grimsby was hit by petrol bombs last month.
Mosques in Essex and Kent have also been targeted.BLOG COMMENTS POWERED BY DISQUS