An improvised explosive device detonated aboard a subway in London during the Friday rush, sending British police on a manhunt in what was being investigated as a terrorist incident, NBC News reported.
At least 29 people were injured in the blast at Parsons Green Tube station in the southwestern part of Britain's capital, though authorities said that none were serious and life-threatening.
On Friday evening, the prime minister raised the threat level from international terrorism from severe to critical — the highest level and an indicator that "an attack is expected imminently."
The Islamic State group claimed responsibility for the bombing, according to the Associated Press.
No arrests have been made, and police would not comment on the manhunt. A flaming bucket was seen with what appeared to be wires protruding from the bag holding it was seen in a photo shared on social media. The train did not appear extensively damaged.
The explosion triggered a stampede as people fled. Emma Stevie, a 27-year-old makeup artist, was confronted with a "human crush of people" at the station.
"Within five seconds my whole day had changed, I thought maybe my life had changed. I just had this feeling, 'Was I going to die?'" she said.