British police have searched five homes in what they say is a significant part of their investigations into last Thursday’s London bomb attacks. Detectives from London combed properties in Yorkshire, in the north of England, armed with warrants issued under the Terrorism act. It is the first reported swoop in what police are describing as the biggest crime scene investigation in English history.Police were acting on an intelligence report, a spokesman said. No arrests have been made so far. At least 52 people are confirmed dead after bombs were detonated on three underground trains and a double-decker bus. Emergency numbers have been posted for families worried about missing relatives. More than 700 people were injured, some seriously, and the death toll is expected to rise. Floral tributes to the dead are continuing to pour in. A Europe-wide investigation is under way with police working their way painstakingly through the wreckage and through thousands of closed circuit television tapes.