UPDATE: Armed counter-terror police search house in Surrey in Parsons Green bomb probe

LATEST: An armed police operation is under way by counter-terror officers investigating the Parsons Green bombing.

UPDATE 3.45pm: An armed police operation is under way by counter-terror officers investigating the Parsons Green bombing.

A house is being searched and residents close to the address in Sunbury-on-Thames, Surrey, are being evacuated, Scotland Yard said.