British police said they arrested four men on suspicion of the commission, preparation or instigation of acts of terrorism.
The men were detained by Metropolitan Police counter terrorism officers at 7.10 pm local time (1810 GMT) and are being held at a south London police station, the force said yesterday in a statement.
Armed officers were involved in the arrests, according to the statement.
Two of the men were arrested in Wapping, east London, one was detained in Peckham, south east London, and the fourth man was picked up in Paddington, west London.
Police said searches under the Terrorism Act 2000 were being carried out at six addresses in London.
