Britain's interior minister and police were meeting social media companies Thursday in the wake of riots this month to discuss how to block access for people using them to plot violence. Home Secretary Theresa May was to chair a discussion with companies including BlackBerry, whose encrypted instant chat service took much of the blame for allowing rioters to coordinate the four nights of unrest in England, officials said. Social networking sites Facebook and Twitter would also be represented at the central London meeting, said a statement from the Home Office. "Amongst the issues to be discussed is whether and how we should be able to stop people communicating via these websites and services when we know they are plotting violence, disorder and criminality," added a spokesman. The talks would help the government "determine how law enforcement and the networks can work better together," he continued. However he stressed that social networks were "not a cause of the recent disturbances but a means of enabling criminals to communicate. "We are working with the police to see what action can be taken to prevent access to those services by customers identified as perpetrators of disorder or other criminal action." Facebook said in a statement ahead of the talks it would be explaining "measures we have been taking to ensure that Facebook is a safe and positive platform for people in the UK at this challenging time." There were calls to temporarily suspend BlackBerry's messenger service during the riots that first erupted in the London district of Tottenham on August 6 and spread to other cities in England, leaving five people dead and shops and flats looted and burned. David Lammy, an opposition lawmaker from Tottenham, urged a shutdown, saying criminals were using the service to outwit police. The messenger service remained up and running throughout the unrest, however. There was no suggestion from the Home Office, the interior ministry, that the total shutdown of networks during future unrest was on the agenda at Thursday's talks. The idea of a total shutdown was floated by Prime Minister David Cameron in the wake of the riots