A second man has been arrested over Friday's bombing of a London commuter train that injured 30 people and Britain remained on its highest level of alert on Sunday with soldiers helping provide security.
The 21-year-old man was detained under Britain's Terrorism Act in the west London suburb of Hounslow just before midnight Saturday, the Metropolitan Police said in a statement.
Police arrested an 18-year-old man in the departure lounge of Dover port earlier Saturday in what they called a "significant" step and then raided a property in Sunbury, a town near London and about 4 miles (6 km) from Hounslow.