Police said on Wednesday that a suicide bomb attack killed six civilians outside a US military base in eastern Afghanistan.
Wednesday's assault comes a day after militants tried to storm government buildings in the same area.
US forces said that they were still gathering information about Wednesday's incident and could not immediately comment.
Wazir Pacha, a police spokesman for eastern Khost province, said that a vehicle drove up to the first gate outside Camp Salerno, on the edge of Khost city, and exploded. Pacha said that at least six civilians died in the blast and 16 others were wounded.