There are Islamic State Brussels-style terror cells operating in England, America's intelligence chief has warned.

James Clapper said there was a "fundamental conflict" between national security and freedom of movement across the European Union.

The director of National Intelligence said that so-called Islamic State had taken advantage of the refugee crisis in Europe and there was evidence of plotting.

Asked if IS cells like those in Brussels existed in England, Germany and Italy, he replied: "Yes, they do. That is a concern of obviously ours and our European allies."

He added: "We continue to see evidence of plotting on the part of Isil in the countries you name."

Mr Clapper said the US was "doing all we can" to share information about IS with their intelligence counterparts.

EU governments were increasingly aware the jihadists were exploiting the migrant crisis," he said.

"They have taken advantage to some extent of the migrant crisis in Europe, something which the nations have a growing awareness of."