Seven people arrested in raids following the Westminster attack that left four dead, British police said.
British Acting Deputy Commissioner and Head of Counter Terrorism Mark Rowley said hundreds of detectives have worked through the night, carrying out searches at six addresses, the (BBC) reported. Seven of the injured are still in hospital in a critical condition. 
Rowley has previously stated that there are no plans to deploy military officers in the British capital to provide additional protection at the moment. This attack was the biggest since the terrorist attack on London's public transportin July 2005 that killed 52 people. 

Source: QNA