A roadside bomb exploded near a convoy of Afghan police in eastern Afghanistan on Friday, killing three officers and wounding two others, a senior police official said. No one claimed responsibility for the attack in Khost province, about 150 kilometres south of Kabul, but Mohammed Ayub, the provincial police chief, blamed Taliban, although he offered no evidence. "It is the work of the Taliban," he said, adding the dead and injured had been transported to a hospital.