British police arrested an 18-year-old man in the port of Dover and raided a house in a small town outside London on Saturday as they hunted for whoever planted a bomb on a commuter train that injured 30 people a day earlier, Reuters reported.
Prime Minister Theresa May put Britain on the highest security level of “critical” late on Friday, meaning another attack may be imminent, and deployed soldiers and armed police to strategic locations such as nuclear plants and defense sites.
In what authorities called a “very significant” development, officers arrested a man at about 7.50 a.m. (0650 GMT) in Dover, from where passenger ferries sail to France. Five hours later they raided a property in Sunbury, a commuter town southwest of London, and evacuated nearby premises as a precaution.
Reuters photographs showed police cordons in a modest suburban street in Sunbury, in the county of Surrey, around 11 miles (18 km) from Parsons Green where the bomb exploded.
“This is a very significant arrest. The police have made very good progress but the operation is ongoing,” said interior minister Amber Rudd, adding that the threat level remained at “critical”.
“There is no doubt that this was a serious IED (improvised explosive device) and it was good fortune that it did so little damage.”
In what was the fifth major terrorism attack in Britain this year, the home-made bomb shot flames through a packed commuter train during the Friday morning rush hour in west London but apparently failed to detonate fully.