Across Britain one man has been murdered, one mosque firebombed, a Sikh temple attacked and other buildings and individuals targeted, the Muslim Safety Forum (MSF), an umbrella group of Muslim organisations which advises the police, said on Thursday.
There have been more than 230 "faith-related" crimes recorded by London police since the 7 July bomb attacks on the city's transport system that killed 52 people and which police say were carried out by four British Muslims.
That compares to just 36 during the same period last year.
"We are getting a lot of concerns and fears, particularly from women," an MSF spokesman said.
"Historically there's always been an under-reporting of incidents. The estimate could be five to 10 times higher."
Another group, the Islamic Human Rights Commission (IHRC), said its caseload had soared.
"We used to get five to six cases referred to us a week. Now we are getting 100," its chairman Massoud Shadjareh said.
Incidents against minorities
include assaults and verbal abuse
But London police chief Ian Blair said racially and religiously motivated crime remained at a low level for a large city, despite an increase following the 7 July bombings and a failed second wave on 21 July.
He also noted the statistics could fluctuate significantly on a daily basis.
"At its peak ... the racist crime reached about 65 offences (per day) immediately after 21 July across London in comparison to what had previously been an average of 40," he said.
The reported incidents have varied from assaults and verbal abuse to a handmade poster being pushed through a Muslim family's door reading "Al Qaeda bomber - move or die".
Call for resignation
Meanwhile, a politician said on Thursday that the head of one of Britain's biggest mosques should resign for calling Prime Minister Tony Blair a liar and questioning whether Muslims carried out the London bombings.
Khalid Mahmood, a Labour Party member of Parliament from Birmingham in central England, said remarks by Mohammed Naseem, chairman of the city's Central Mosque, were “wholly unacceptable.”
”In light of what he has said, he certainly should resign,” Mahmood said.