Police believe at least one of four British-born London bomb suspects died in the tube and bus blasts

BBC News:

Security sources said it was likely three men whose belongings were found at the scenes are dead - there is a question mark about the fourth bomber.

Police, who have arrested a relative of one of the suspected bombers in Yorkshire, say they have CCTV image of the four arriving in London on the day.

Explosives material has been found in Leeds following raids there on Tuesday.

Police said the material found was a "significant amount".

Four bombs - three on the London Underground and one on a bus in Tavistock Square in the city centre - claimed the lives of at least 52 people on Thursday.

The breakthroughs in the anti-terror investigation came after a day of raids in the Leeds area and the seizure of a car at Luton rail station.

There is no identity for the fourth bomber and police do not know if his remains are at the King's Cross blast site or if he has fled.

One man was arrested in Yorkshire and taken to London for questioning following the police operations on Tuesday.

BBC Home Affairs correspondent Margaret Gilmore said security sources suspected all four men died.

Head of the Metropolitan Police anti-terrorist branch Peter Clark said they could not yet confirm this.

But he said documents identifying three of the men were found near three blast sites.

Three of the four men were from the West Yorkshire area said Mr Clark.

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