British anti-terrorist police arrested a man Tuesday in connection with the attempted bombings of London's transit system on July 21.
The man was arrested at Gatwick Airport as he got off a flight from Addis Ababa, Ethiopia, London's Metropolitan Police said.
The 23 year-old is suspected of the commission, preparation or instigation of acts of terrorism and was being questioned Tuesday at central London's high security Paddington Green police station.
Scotland Yard police headquarters said he had been out of Britain since June. The alleged role played by the man was not immediately clear. One of the alleged attacks was born in Ethiopia.
A total of 15 people have been charged in connection with the July 21 attacks on three subway trains and on a double-decker bus. The attempted attacks did not kill anyone as the bombs failed to detonate, but they shook Britain's capital two weeks after near identical suicide bombings killed 52 commuters.