A sledgehammer-wielding man was seen smashing windows at two mosques in Britain's second city Birmingham and three more have been similarly vandalised overnight, the police said Thursday.
Counter-terrorism officers are investigating attacks on the mosques in different areas in the central English city, West Midlands Police said in a statement.
The force added the incidents were "being treated as linked".
"We don't know the motive for last night's attacks," said Chief Constable Dave Thompson in a statement.
"The force and the counter terrorism unit are working side-by-side to find whoever is responsible."
The mosque and community centre on Albert Road in Birmingham where a police forensic team are at work after it had its windows smashed with a sledgehammer. Source: AAP
Officers were first alerted in the early hours of Thursday to reports of a man smashing windows with a sledgehammer at one of the places of worship, police said.
Following reports of a similar attack at another mosque in a nearby neighbourhood, officers launched targeted patrols and discovered "further damage" at two other sites.
A fifth mosque later reported that windows had been smashed.
"Forensic officers are working to identify evidence, and CCTV is being examined," the West Midlands force added.
Some 22 percent of the Birmingham population described themselves as Muslim in the 2011 census.
British national police chiefs last week announced officers were providing "reassurance patrols" around mosques in the immediate aftermath of Friday's deadly gun rampage at two mosques in Christchurch, New Zealand.
Anti-racism groups have warned that Islamophobia is on the rise in Britain and spurring a spike in far-right activity in the country.
A report released last month by the Hope Not Hate charity cited a poll which found more than a third of Britons see Islam as "generally a threat to the British way of life".
In another recent incident, Mohammed Mahmoud -- an imam who won praise for shielding the perpetrator of a 2017 deadly terror attack against a north London mosque -- reported he was spat at and abused this week.
Mahmoud said he was targeted Monday while returning home from a solidarity event for the New Zealand massacre with other religious leaders, as well as interior minister Sajid Javid and London Mayor Sadiq Khan.
