LONDON - Britain is considering ways to disrupt online social messaging and networks such as Blackberry Messenger and Twitter during civil unrest, a government source said on Thursday.

Police have said social networks were used by rioters to co-ordinate looting during four days of disorder across England this week.

"We know this was used ... the question is can you do something to disrupt that in a way that deals with these problems?" the source said.

"We are having conversations with intelligence services and the industry. We are not proposing anything yet."