The terror threat in the UK has been raised to its highest level as a manhunt continues for the bomber who left a home-made device on a London tube train.
The so-called Islamic State group said it was behind the attack which injured 29 people at Parsons Green station at rush-hour on Friday morning.
Pictures taken at the scene showed a slightly charred white bucket with a supermarket freezer bag on the floor of one train carriage. The bucket, still intact, was in flames and there appeared to be wires coming out of the top.
The device could have been deadly but failed to fully detonate.
“We are chasing down suspects,” said Britain’s top counter-terrorism officer, Mark Rowley.
“Somebody has planted this improvised explosive device on the Tube: we have to be open-minded at this stage about him and about potential associates.”
“The Joint Terrorism Analysis Centre, that’s the independent organisation which is responsible for setting the threat level on the basis of intelligence, has now decided to raise the national threat level from severe to critical,” British Prime Minister Theresa May announced on Friday evening.
“This means that their assessment is that a further attack may be imminent.”
A Tweet from US President Donald Trump, suggesting that the suspect was known to police, earned him a rebuke from Mrs May.
“Another attack in London by a loser terrorist,” Trump wrote.
“These are sick and demented people who were in the sights of Scotland Yard. Must be proactive!”
May reacted by saying: “I never think it’s helpful for anybody to speculate on what is an ongoing investigation”.
Trump later tweeted a message of support to the people of London.
Joined by ministers and senior police officers, Prime Minister May chaired a meeting of the government’s emergency response committee.
This was Britain’s fifth major terrorism incident this year and, had the device gone off as planned, it could have caused mass carnage.
As it happened, some passengers suffered burns and others were injured in a stampede to escape the station, but health officials said none were thought to be in a serious condition.