Dafne Cholet/Flickr British police are arresting people in the middle of the night if they have made racist or anti-Muslim comments on Twitter following the murder of a soldier by two Muslims in Woolwich, London.

Three men have so far been taken into custody for using Twitter and Facebook to criticize Muslims.

In the Woolwich attack, Lee Rigby, a drummer in the Royal Regiment of Fusliers, was run down in a car and then hacked and stabbed to death by two men with knives and a cleaver. They told a man video recording the scene that it was vengeance for the killings of Muslims by the British Army.

One man has been charged with "malicious communications" on Facebook, the Daily Mail reports.

Two others have been arrested under the Public Order Act on suspicion of inciting racial or religious hatred. The police are now arresting people based on mere speech in social media, a detective said in a statement to the press:

'The men were arrested under the Public Order Act on suspicion of inciting racial or religious hatred. Our inquiries into these comments continue.

'These comments were directed against a section of our community. Comments such as these are completely unacceptable and only cause more harm to our community in Bristol.

'People should stop and think about what they say on social media before making statements as the consequences could be serious.'

The arrests come at the behest of British Muslims, who fear a backlash against them following the death of Rigby, The New York Times says:

The police and Muslim groups have said that there have been anti-Muslim episodes in many parts of the country, the most common involving derogatory messages on social media sites like Twitter and Facebook.

A number of arrests have been made, with criminal charges being leveled in some cases under laws against inciting racial or religious hatred, and Muslim community leaders have reported rising concern among the estimated 2.5 million Muslims in Britain.

Two men were detained in the middle of the night after they expressed anger at Muslims on Twitter. The Independent quotes police as saying:

"We began inquiries into the comments and at around 3.20am two men, aged 23 and 22, were detained at two addresses in Bristol.

"The men were arrested under the Public Order Act on suspicion of inciting racial or religious hatred. Our inquiries into these comments continue."