A second man has been arrested in connection with Friday's attack on a London underground train, police said Sunday morning.
The 21-year-old man was arrested in Hounslow, west London, on Saturday night. He was arrested under Section 41 of the Terrorism Act and has been taken to a south London police station where he remains in custody.
The arrest came as a nationwide manhunt is underway in the country after the bombing was declared a terror attack.
An 18-year-old man is being held after being arrested on suspicion of a terror offence at the Port of Dover earlier on Saturday.
Thirty people were injured after the explosion on a tube train at Parsons Green Friday morning.