British police have arrested two more men in connection with the bombing of a commuter train in London last week which injured 30 people, bringing the total in custody to five.

The men, aged 48 and 30, were held under terrorism laws in Newport in south Wales.

Another man was arrested in Newport on Tuesday night while two others, an 18-year-old and a 21-year-old, were held by counter-terrorism officers on Saturday.

“This continues to be a fast-moving investigation. A significant amount of activity has taken place since the attack on Friday,” said Dean Haydon, head of the Metropolitan Police’s Counter Terrorism Command.

“We now have three men in custody and searches are continuing at four addresses. Detectives are carrying out extensive inquiries to determine the full facts behind the attack.”

The home-made bomb went off on Friday during the morning rush hour on a packed train at Parsons Green underground station, engulfing the carriage in flames.

A total of 36 people have been killed in Britain this year in militant attacks.