Mosques outside London were also attacked after the bombings

There were 269 religious hate crimes in the three weeks after 7 July, compared with 40 in the same period of 2004.

Most were verbal abuse and minor assaults, but damage to mosques and property with a great "emotional impact" also occurred, police said.

Met Police Assistant Commissioner Tarique Ghaffur said he had never seen so much anger among young Muslims.

It [religious hate crimes] can lead to these communities completely retreating

Assistant Commissioner Tarique Ghaffur

Communities were particularly frustrated by the increased use of stop-and-search and the new "shoot-to-kill to protect" policy of dealing with suicide bombers, he said.

"There is no doubt that incidents impacting on the Muslim community have increased."

However, Mr Ghaffur also pointed out that the rise was partly due to the fact that faith hate crimes were now recorded separately from other racial incidents.

And he warned: "It can lead to these communities completely retreating and not engaging at a time when we want their engagement and support."

Mr Ghaffur revealed that in the first three days after suicide bombers killed 52 people and injured 700 more, there were 68 "faith hate" crimes in London alone.

Racial profiling

A spokesman for the Muslim Safety Forum, an umbrella group which works closely with the police, said the figures reflected the increase in calls to their members about abuse and attacks since the London bombings.

"It's something we've been saying for a few weeks now but it's good to see senior police managers like Tariq Ghaffur have got up and actually said it," spokesman Tahir Butt said.

"Although police are talking about a zero tolerance policy the test is how effective that is at ground level when you go in and report a crime," Mr Butt added.

But chairman of the Metropolitan Police Authority Len Duvall said that although any hate crime was not to be tolerated, many incidents previously defined as race crimes were now designated faith crimes, leading to a "large percentage increase from a very low base".

Faith hate crimes are currently prosecuted under anti-racism legislation, but a bill to create a new offence of incitement to religious hatred is currently going through the Houses of Parliament.

The bill, which has attracted criticism from many quarters, has passed its Commons stages but is set to get a rocky ride in the Lords.

The alarming figures emerged as Home Office minister Hazel Blears held the first in a series of meetings on Tuesday with Muslim community groups across the country.

Those meetings come amid increasing concerns that young Muslims are being targeted by police in stop-and-search operations.

There may be longer term implications if this level of activity continues

Assistant Commissioner Ghaffur

Ahead of the meeting, Ms Blears pledged that Muslims would not be discriminated against by police trying to prevent potential terror attacks.

She insisted "counter-terrorism powers are not targeting any community in particular but are targeting terrorists".

She also opposed police use of racial profiling, saying stop and searches should be based on good intelligence, not just skin colour.

Mr Ghaffur also revealed that the specialist unit dealing with serious and organised crime had lost 10% of its staff to the bombings inquiry.

'Stretched'

Between 300 and 473 of Specialist Crime Directorate detectives have been seconded at any one time since 7 July.

As a result Mr Ghaffur said key leads would be followed up but proactive work on major murder inquiries had "slowed to a trickle".

These include the 2004 murder of Amelie Delagrange, linked to five other attacks on women in south-west London, and the 1992 murder of Rachel Nickell on Wimbledon Common.

"The Met is stretched," he said. "There may be longer term implications if this level of activity continues."

Last week Met Commissioner Sir Ian Blair revealed the anti-terrorism investigations were costing £500,000 a day.