Where does this door lead?
Apparently it used to be on the house where a suspect in the London bombing was arrested.
Police have arrested one of the four men they believe to be responsible for the July 21 attempted bombings of London's mass transit system, British media reported.
The Metropolitan Police said four men were detained in Birmingham, about 100 miles north of London, early Wednesday in connection with the attacks.
However, police would not confirm media reports that one of the men arrested, and later taken to London for questioning, was among those being sought in connection with the failed bombing.
CNN's Senior International Correspondent Nic Robertson said: "The fact that one of those arrested has been brought to London indicates that he is central to the police investigation."