'Gun shots and explosions' have been reported in Westminster after a suspect package was found less than a mile from where the London terror attack unfolded.

Witnesses reported the explosion at 8.30pm tonight and police confirmed that they had found a package close to Downing Street.

A Met Police spokesman claimed that no explosion has taken place on Birdcage Walk, near where mourners have gathered for a vigil in Trafalgar Square.

The force later revealed that an unattended bag had sparked the alert.

Witnesses reported the suspect package had been found in Westminster tonight

The discarded bag was found close to Horse Guards Road, next to St James' Park, police confirmed

A Metropolitan Police spokesman told MailOnline that officers had been called after a suspect package was found in Birdcage Walk, close to Buckingham Palace.

The road runs from the landmark, down past the Palace of Westminster, and turns into the A302, which goes over Westminster Bridge.

Four people were killed when the attacker mowed down pedestrians and cyclists on the bridge then stabbed an officer by the gates of the Houses of Parliament.

Two civilians injured on the bridge died, as well as the policeman and Masmood, who was shot by another officer moments after stabbing his colleague.

Paul Abernethy‏ wrote on Twitter: 'Down in Westminster, just heard what sounded like an explosion. Not sure what happened though. Police said they were dealing w/ new incident.'

Sky News producer Pia Talbot claimed that police told them they had carried out a controlled explosion within earshot of their crew.

A police spokesman said: 'Officers were called at 7.40pm, he stated.

He said: ‘In this case we are dealing with a suspect package.’

The spokesman said police would not be releasing further information.