Police forces across the country have recorded a surge in anti-Muslim hate crimes.

In many areas, a steep rise in the number of Islamophobic attacks was recorded in the wake of the murder of soldier Lee Rigby in May, by two Islamic extremists in south London.

In London alone Britain's biggest force, the Metropolitan police, recorded
500 Islamophobic offences from January to mid-November this year, compared with 336 offences in 2012 and 318 in 2011.

In May alone, directly after the Rigby murder, Scotland Yard recorded 104 anti-Muslim hate crimes, followed by another 108 in June.

Greater Manchester Police, and Kent Police said that the number of ant-Muslim hate crimes had more than doubled in a year, with spikes recorded after May.

Forces in West Yorkshire, Leicestershire, Thames Valley, Cheshire, Merseyside and Humberside were amongst those to also report increases.

However, only half of the UK's 43 forces record details of religious hate crime victims, meaning the real figures may be much higher.

Tell Mama, a group which monitors anti-Muslim hate crimes, said that it had dealt with 840 cases since April, with the number expected to rise to more than 1,000 by the end of March. This compared with 582 anti-Muslim cases it dealt with from March 2012 to March 2013.

In the last year, there have been a number of high profile attacks on Mosques.

The most recent came in August, when a mosque in Harlow, Essex, was torched.

In the weeks after the murder of Rigby, there were attacks on mosques in Essex, Kent, and Grimsby, Lincolnshire.

A mosque in Muswell Hill, London, was firebombed in June, and later that month petrol poured around the door of a mosque in Gloucester and set alight.

Fiyaz Mujhal, director of Faith Matters, which runs the Tell Mama project, said that far right groups were using the internet to add to tensions caused by the murder of Rigby, and called for tougher sentences for those found guilty of targeting Muslims.

"The far right groups, particularly the EDL [English Defence League], perniciously use the internet and social media to promote vast amounts of online hate," he said.

"In one case, a pig's head was left outside a mosque and the perpetrator came away with a community sentence. When you target a mosque, you are targeting the whole community," he told the Guardian.

Mr Mujhal called on police forces to improve their ability to identify anti-Muslim hate crimes, and make the way they are recorded more consistent.

"There must be guidelines for all forces so we can know the level of the problem," he said.

Superintendent Paul Giannasi, spokesman for the Association of Chief Police Officers, urged victims to come forward.

"We would obviously want overall crime levels to reduce and to see fewer victims, but we welcome increases in reported hate crime, as long as they are a sign of increased confidence of victims to report.

"We are working with local police forces, to help improve the way we respond to hate crime and to provide robust and transparent hate crime data," he said.