London police made a number of arrests in the capital's suburb of Notting Hill and at a downtown train station in search for July 21 bombing suspects.
Police would not say who was arrested, but British broadcast media reported that at least two of the three men being sought for the failed bombings had been arrested. That would bring the number of arrests of men tied to the July 21 attacks to three. Another suspect was arrested in Birmingham on Wednesday.
Britain's Sky News television showed images of two men in protective suits used by forensic teams to preserve evidence escorting a third similarly clad man out of a building in the Notting Hill area.
Armed police also arrested two women at Liverpool Street station, located in central London, and evacuated the area. The women were pinned to the ground in a raid.
One woman was said to have been in line for the Stansted Express, a train which goes to one of London's peripheral airports, when she was pushed to the ground by police.
British Transport Police said the operation was carried out by the Metropolitan Police and confirmed that the site was being searched. Both the mainline station and its Underground station were evacuated.
"The two women were arrested at around 1:54 p.m. (1254 GMT) and the station is now closed, the Tube is passing through on a nonstop basis," a BRT spokesman said on condition of anonymity in accordance with British practice. "Police are now looking at a number of suspect packages and searching the station."
The July 21 attacks targeted three undergound trains and a bus, but there were no victims and police said the explosive devices failed to properly detonate, the AP reports.