Details emerging about nature of Britain bombings

? Police radically revised the timing of the deadly blasts that tore through the London Underground, saying Saturday that the bombs were detonated just seconds apart – not 26 minutes as first reported. The explosions were so intense that none of the 49 known dead has yet been identified.

Many bodies still lay buried in a rat-infested subway tunnel and frantic relatives begged for word about others still missing in the worst attack on London since World War II. Police indicated as many as 50 additional victims were unaccounted for.

Deputy Assistant Police Commissioner Brian Paddick said the near-simultaneous nature of the attacks Thursday indicated timers – not suicide bombers – set off the explosions. He cautioned, however, that the investigation was in an early stage and nothing had been ruled out.

Investigators also said the bombs that brought the British capital to a standstill were made of sophisticated high explosives. Investigators said it was too early to pinpoint where the terrorist bombers got the ingredients.

Investigators repeated their assertion that the bombings bore the signature of al-Qaida. The organization, headed by Osama bin Laden, has gained a reputation for sophisticated timing in its terror strikes.

Transit officials originally said Thursday’s blasts occurred over a 26-minute span, but computer software that tracked train locations and electric circuits subsequently determined the first blast shattered the rush-hour commute at 8:50 a.m. in Aldgate station, east London, with the next two erupting within 50 seconds.

A fourth explosion tore through a double-decker bus near a subway entrance, killing 13 people, nearly an hour later.