Which of the following statements is NOT true about the bomb blasts in London?

A clearer picture is emerging of events surrounding the bomb blasts that ripped through three London underground trains and a double-decker bus, killing more than 50 commuters, on 7 July. Analysis of emergency calls and other technological evidence now suggest that the blasts all occurred within just 50 seconds, rather than the 26 minutes first reported. The police drastically revised the timeline for the first three explosions at a press briefing held on Saturday.