British police have arrested a second man over the bombing of a London commuter train that injured 30 people as security services lowered the threat level for an attack from its highest setting.
London police said in a statement that the 21‑year‑old man was detained under Britain's terrorism laws in the west London suburb of Hounslow.
Police earlier arrested an 18‑year‑old man in the departure lounge of Dover port in what they called a "significant" step and then raided a property in Sunbury‑on‑Thames, a town near London and about 6km from Hounslow.
The home‑made bomb shot flames through a packed carriage at west London's Parsons Green Tube station during the Friday morning rush hour but apparently failed to detonate fully.
Interior minister Amber Rudd said the second arrest showed it was not a lone‑wolf attack but there was no evidence Islamic State was involved.
