At least 10 people were killed when a man wearing a suicide vest and riding a bicycle blew himself up, The New York Times reported.
Charlie Stadtlander, a spokesman for the international military mission in Afghanistan, said there was no apparent connection between the bombing and Hagel's visit, but the Taliban -- in a statement taking responsibility -- called it a "message" to the new defense secretary, Voice of America reported.
The Times reported a ceremony to mark the transfer of full control of Bagram Prison to Afghanistan was canceled Saturday for reasons that were not immediately clear. The newspaper said the cancellation created a cloud of doubt about the U.S.-Afghan agreement on custody of the remaining Afghan prisoners held by American forces.
The Times said while there was no official word on the cancellation, it would likely have the effect of embarrassing Afghan President Hamid Karzai, who rankled American officials Wednesday when he criticized the Americans' slowness on the detention issue and promised to release many of the prisoners as soon as the transfer was complete.
A police officer and eight children were killed in a bombing in Khost province, officials said. Yaqub Mandozia, the deputy provincial police chief, said the officer probably prevented an even higher death toll by wrapping the bomber in a bear hug as he blew himself up, the Times said.