What happened last week in London?

British police officers cordon off the scene of a police raid in an apartment block in west London. London police hunting for suspects in last week’s failed bombing attempts on the city’s transport system are conducting a number of high-profile operations around the capital.
    As police barked out orders to passersby, teams of armed officers conducted raids across London in the search for three men suspected of planting bombs that failed to explode on subway trains and a bus on July 21.
    Police say there have been a number of arrests in the operations in London’s Kensington and Noting Hill neighborhoods, and at the Liverpool Street train station in the city’s financial district.
    London media say one or more of the three would-be bombers could be among those arrested, but there was no official police confirmation of those reports.