London police have arrested a second man in connection with Friday’s terror attack on the London Underground, which left nearly 30 people injured in a train car.
Police announced Sunday morning that a 21-year-old man was arrested in Hounslow, a borough in west London, before midnight on Saturday.
The man, who has not been identified, is being held under the Terrorism Act, as is an 18-year-old suspect police arrested Saturday morning in the Port of Dover in connection with the bombing.
Police also raided and searched a house in Sunbury, west of London, on Saturday afternoon as they investigate who may have been involved in the explosion, reports said.
A homemade bomb exploded on a train at the Parsons Green station Friday morning, leaving 29 people injured, including a child.
Witnesses said the carriage was engulfed in flames, and dozens of passengers were trampled as they tried to escape, The New York Times reported.
Police have said the bomb did not detonate properly, and if it had, it would have caused much more damage.
On Saturday, Home Secretary Amber Rudd said that it was “good fortune” the improvised explosive device “did so little damage,” but she said that the materials used to build the bomb were too readily available.
“We have to make certain we take all the steps we can to ensure that the sort of materials this man was able to collect become more and more difficult to combine together,” Rudd said.
For investigative reasons, police said they are not giving out details on the man they arrested.
London remained on high alert Sunday and authorities said they placed extra officers on duty at train stations.
ISIS has claimed responsibility for the attack.