Encouraging division over Islam has been the primary tactic of Russian trolls targeting Britain on Twitter, according to research.

Tweets about Islam far outnumbered those about Brexit and were also more widely shared, an analysis of nine million posted by a troll factory in St Petersburg found. Last month Twitter released the dataset of the tweets, which had been posted by 3,841 blocked accounts affiliated to the notorious Internet Research Agency.

Initial investigations highlighted the prevalence of pro-Leave messages, including a co-ordinated push on the day of the 2016 vote. However, Demos, a cross-party British think tank, has since found that the messages most widely shared related primarily to Islam and stirring up Islamophobia.

The Russian troll accounts with the biggest following were more likely