An investigation involving counter-terrorism officers has been launched after five mosques were vandalised in an "abhorrent, despicable act".
Officers were called early on Thursday morning after four mosques in Birmingham had their windows broken with a sledgehammer overnight.
At 10.04, police then responded to a smashed window at a fifth mosque on Albert Road, Aston, after pictures were circulated on social media.
West Midlands Police said they received reports of an attack on a mosque in Birchfield Road at 2.32am.
Officers then attended a second mosque attack in Slade Road, Erdington, at 3.14am.
Patrols then started in areas with mosques and officers came across further damage in Witton Road, Aston, and on Broadway in Perry Barr.
The force said forensic officers are working to identify evidence and CCTV is being examined.
The attacks are being treated as linked and West Midlands Police and West Midlands Counter Terrorism Unit are yet to establish a motive.
Home Secretary Sajid Javid tweeted: "Deeply concerning & distressing to see number of mosques have been vandalised in Birmingham overnight.
"@WMPolice are investigating motive but let me be clear – hateful behaviour has absolutely no place in our society & will never be accepted."
Outside the mosque on Albert Road on Thursday, Deputy Chief Constable Louisa Rolfe said: "This is an abhorrent, despicable act that is clearly designed to create fear in our communities who are actually cherished in Birmingham.
"My message to them would be, come on, hand yourself in, what a cowardly thing to do and if you have extreme views and things you want to say, come and speak to police about it."
West Midlands Police Chief Constable Dave Thompson said: "Since the tragic events in Christchurch, New Zealand, officers and staff from West Midlands Police have been working closely with our faith partners across the region to offer reassurance and support at mosques, churches and places of prayer.
"At the moment we don't know the motive for last night's attacks.
"What I can say is that the force and the counter terrorism unit are working side by side to find whoever is responsible."
Mr Thompson added: "At difficult times like this, it is incredibly important that everyone unites against those who seek to create discord, uncertainty and fear in our communities."