New video footage released on Tuesday showed three of the men who carried out the suicide bomb attacks in London on July 7 staging a dummy run nine days earlier.

Detectives retraced the men's movements after analyzing tens of thousands of hours of security camera footage as part of the probe into the blasts which killed 52 people, the Scotland Yard said.

The new tape shows three of the gang of four traveled to the capital from Luton on June 28, before travelling to King's Cross and Baker St Tube stations.

Police said they were keen to find out if the men met anyone else on the day.

"What we want to know is where else they went and did they meet anybody else while they were in London," Peter Clarke, head of Scotland Yard Anti-Terrorist Branch, told the BBC.

The July 7 suicide attackers killed 52 innocent people and wounded hundreds other. Three of the four bombers detonated their devices on underground trains, while the fourth exploded his rucksack bomb on a bus.

Clarke said the investigation would carry on for months. More than 3,000 plus witness statments had been gathered and 80,000 security camera tapes analyzed.

Detailed scrutiny of CCTV film recovered from Luton train station has revealed that Mohammed Sidique Kahn, Shahzad Tanweer and Germaine Lindsay met at approximately 8:10 am on June 28.

They bought tickets and shortly boarded a Thameslink train to London King's Cross where further CCTV shows them arriving and moving through the train station at approximately 8:55.

The three men are then seen together again at Baker Street station at around mid-day and back at King's Cross station at 12: 50. They boarded a Thameslink train to return to Luton, arriving back at approximately 13:40.

Earlier this month, a video suicide message from Khan emerged in which he claimed that the British public were to blame for the terror attacks.

Al-Qaida's deputy leader has claimed that the terror group was behind the London bombings on a videotape aired Monday on Arabic TV channel al-Jazeera.

Source: Xinhua