A new police unit is being set up across Europe to uncover and block social media accounts being used by Islamic State (IS).

The European police agency Europol will target the estimated 40,000 to 50,000 accounts linked to the terrorist organisation.

Working with unnamed social media companies, it aims to shut down the accounts within two hours of them being discovered.

Calls for more to be done to tackle online radicalisation have mounted in recent weeks after claims that Talha Asmal, who was reported to have become Britain's youngest suicide bomber, was groomed over the internet.

Talha, 17, is alleged to have fled his home in Dewsbury, West Yorkshire, in March to join IS and reportedly detonated a vehicle while fighting for the group in Iraq.

His family said he had been exploited by extremists on the internet "in a process of deliberate and calculated grooming".

Rob Wainwright, Europol's director, said the new unit, which comes into force on July 1, would work to identify the key accounts being run in a number of languages that "underpin" what IS is doing and would aim to "identify the ringleaders online".

He told the Guardian it would also monitor social media to identify any activity targeting people who might be vulnerable, as well as those preying on them.

He said: "Who is it reaching out to young people, in particular, by social media, to get them to come, in the first place? It's very difficult because of the dynamic nature of social media."