Police identifies London Tube bombing suspect

The suspect was identified as 21-year-old Syrian refugee Yahyah Farroukh. His arrest took place at midnight Saturday outside a fried chicken shop in Hounslow, West London. Metropolitan Police officers were still searching the area on Monday morning, the Guardian reported.

Farroukh is believed to be from the Syrian capital of Damascus originally and has lived in Britain for at least four years. Officers were also searching an address understood to be Farroukh's home in nearby Stanwell, in Surrey, only metres from the outer boundaries of Heathrow airport.

He previously stayed at the Sunbury house of Ronald Jones, 88, and his wife, Penelope, 71, who have been fostering at least 268 children over the past four decades, including refugees from Eritrea, Iraq, Somalia and Syria, according to reports.

Farroukh's arrest came after an 18-year-old unnamed chief suspect was detained at Dover ferry port on Saturday, hours after the explosion on the packed rush-hour carriage at Parsons Green subway station injured some 30 people.

The attack was claimed by the Islamic State terror group.

Both men remain in custody under section 41 of the Terrorism Act 2000, which allows police to detain suspects without charge beyond the four days allowed for suspects connected to other crimes.

British Home Secretary Amber Rudd claimed the two arrests as "good progress" in the inquiry. The terrorist attack was caused by an improvised explosive device, which had a timer, but failed to fully detonate.

"The joint terrorist analysis centre, which reviews the threat level that the UK is under, has decided to lower that level from critical to severe."

The "severe" level means another attack is highly likely but the higher "critical" level means an attack may be imminent.

Rudd said that it appeared the bomber was not a lone wolf but added that it was "too early to reach any final conclusion on that".

Assistant Metropolitan Police Commissioner Mark Rowley said police had gained a "greater understanding" of how the bomb was prepared but said there was "still much more to do".

Previous attacks in London this year at Westminster Bridge, London Bridge and Finsbury Park as well as a blast at an Ariana Grande concert in Manchester killed dozens of people and injured more than 150.