Officials have confirmed that two men arrested by armed police in London are suspected Basque terrorists.
Antonio Troitino Arranz and Ignacio Leron Sanchez are described as senior members of ETA by the Spanish interior ministry.
They were arrested at a residential address in Hounslow, west London.
Armed officers joined those from the counter terrorism command when the arrests were made at about 4am.
Police say the operation was not linked to the Olympics.
A 38-year-old woman was also arrested for alleged fraud offences and two other men were held over alleged immigration offences.
The men, aged 39 and 55, were picked up by officers from Scotland Yard's counter terrorism command.
Both are being held under the Extradition Act after being arrested at a residential address in west London.
Scotland Yard says two Spanish nationals have been arrested in London in connection with alleged terrorist offences in Spain.