Twitter users in the United Kingdom who posted inflammatory messages encouraging others to engage in violence could be arrested, according to Scotland Yard Deputy Assistant Commissioner Stephen Kavanagh.
Kavanagh told The Telegraph that officers were investigating messages posted on Twitter and would "absolutely" consider arresting users who helped incite some of the worst rioting in the British capital in years.
"That investigation is already under way and that is exactly the sort of thing we are looking at," he said.
The riots broke out in the north London district of Tottenham on Saturday night, following a protest against the death of a local man in a police shooting last week, and the violence spread to other parts of the city on Sunday.
London Fire Brigade received 264 emergency calls overnight Saturday and attended 49 fires in the Tottenham area.
Overnight Saturday, they dealt with 12 fires which damaged shops, vehicles and homes. Three fire engines were damaged in the violence.
"There is simply no excuse for this abhorrent behaviour which endangers the lives of firefighters and also the people they are trying to protect," said London Fire and Emergency Planning Authority leader Brian Coleman.
Police said they had made 215 arrests since the riots began. The youngest person arrested was an 11-year-old boy.
The districts worst hit by the violence -- Tottenham, Brixton in south London, Hackney and Peckham -- are multi-ethnic areas which have high rates of unemployment.