Scotland Yard has confirmed that a suspicious package was found in north west London which may be linked to the four bombs recovered after last Thursday's attempted bomb attacks.
The package was found by a member of the public in bushes in Little Wormwood Scrubs shortly after 10am today.
A man shot dead on a London subway train by British police probing bomb attacks in the city has been identified as a 27-year-old Brazilian, Jean Charles de Menezes.
Police said today Mr de Menezes, who was shot in Stockwell tube station in south London yesterday, was not connected to the investigation into the attempted terror attacks.
The Metropolitan police had earlier arrested a second man in Stockwell, where one man was already in custody on suspicion of the preparation, instigation and commission of acts of terrorism.
He was arrested close to Stockwell Underground station where police shot the other man dead yesterday in an anti-terrorism operation.
Eyewitnesses said an Asian man was pursued by three armed plainclothes officers into Stockwell tube station.
According to one eyewitness on the train two plainclothes officers pushed the man to the floor while a third officer shot the man five times with a semi-automatic pistol.
Meanwhile, police have said they have had an encouraging response from the public following the release of CCTV images of four men, suspected of involvement in the attacks.
They urged anyone who may recognise the men not to approach them but to contact police immediately.
Three of the four devices found on Thursday are thought to be of similar size and weight to the bombs used in the 7 July attacks in which 56 people were killed.
Forensic experts are now trying to establish if the explosive is linked to that found in a house in Leeds following the blasts in London on 7 July