The Taliban has claimed responsibility for the supermarket attack in the Afghanistan capital, declaring that it was aimed at foreigners, in particular the head of the North Carolina-based security firm Xe Services.In a grim demonstration of insurgents' ability to strike even in tightly guarded districts, a suicide bomber blew himself up in a supermarket in a wealthy enclave of the Afghan capital on Friday, killing at least eight people, including three foreign women and a child, and injuring more than a dozen others, police said.