Incidents of arson and criminal damage were reported at mosques in London, Telford, Leeds, Bristol and Birkenhead.
Glasgow's central mosque was also searched and evacuated after police received a call about an incident in the area.
Although the call is being treated as malicious, the increase in disruption is indicative of heightened tensions across the UK.
The Mazhirul Uloom mosque in Mile End, east London, reportedly had 19 windows broken, and damage resulting from an arson attack was caused to the door of the Pakistan consulate in Bradford, where a 27- year-old man was later arrested.
The wide-ranging cast of religious leaders who were signing the book of condolence in City Hall, London, yesterday underlined the need for unity.
Among them was Iqbal Sacranie, secretary-general of the Muslim Council of Britain, who said in a letter to Muslims across the country: "It is the duty of all of us to help bring the perpetrators of this tragedy to justice speedily.
"If they are not caught soon, these criminals may attempt to carry out yet more atrocities in the near future. They must be stopped."
Less than 24 hours after the attack, bottles were thrown at the Jamia mosque in Bristol while, on Sunday, vandals smashed seven windows at the city's Shajalal mosque.
Superintendent Tim Lee, who is investigating the attacks, said: "It is vital that we do not let the terrible events of last week divide our communities."