Scotland Yard said three properties - two in Westminster and one in Barnet are being searched along with a number of cars - after two men were arrested on suspicion of terror offences.
Police said that one of the arrests in Westminster took place at a residential address and not near any major landmark.
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Lord O'Donnell, who used to head up the Civil Service, says he believes Britain may not actually exit the European Union.
The Labour leader said he doesn't believe culture should be just for the elites.
Rain will spread into southern and central England but elsewhere will remain dry with warm sunny spells.