Parsons Green terror attack: Donald Trump labels bucket bomber 'loser' who was 'in sights of Scotland Yard'

Donald Trump has called the perpetrator of a bombing on the London Underground a "loser terrorist" who was "in the sights of Scotland Yard".

It is unclear whether the statement was the result of information he has been passed by aides.

Police said they were treating the explosion, which occurred at around 8.20 at Parsons Green Underground station, as a "terrorist incident" and they have launched an "urgent manhunt" for the bomber.

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"Another attack in London by a loser terrorist," Mr Trump said. "These are sick and demented people who were in the sights of Scotland Yard. Must be proactive!"

Nick Timothy, former joint chief of staff to Theresa May, said it was "unhelpful" of the US President to suggest Scotland Yard had prior knowledge of the Parsons Green suspect.

"True or not – and I'm sure he doesn't know – this is so unhelpful from leader of our ally and intelligence partner," he said in a tweet.

It is not the first time the President has been accused of mishandling classified information. US officials in May said Mr Trump had disclosed highly sensitive information to Russian officials that jeopardised a critical source of intelligence on Isis.

Earlier this year, the UK complained to the Americans after sensitive intelligence and on-scene imagery from the Manchester Arena bombing was published by the US media before British police had released it.

Home Secretary Amber Rudd said she had been given assurances a similar breach of confidence would not happen again.

The Metropolitan Police would not be drawn on Mr Trump's comments on the Parsons Green explosion. A spokeswoman said: "It's not something we would comment on."

Counter-terrorism investigators are looking for whoever carried the homemade device, thought to be in a white plastic container, onto the District line Tube carriage.

The Underground is well covered by CCTV cameras and detectives are examining the footage to find where those behind the explosion entered and exited the network.

Hundreds of detective have been drafted into the investigation, the Met's assistant commissioner Mark Rowley said.

Minutes after sending his first tweet commenting on the Parsons Green attack, the US President sent another, claiming that the internet served a recruitment tool for terrorist groups that "we should cut off & use better". He did not immediately provide details of the proposal.