WASHINGTON (Reuters) - A U.S. citizen was killed in an attack on a United Nations vehicle in Kabul on Sunday, U.S. Secretary of State Mike Pompeo said, as he condemned the act.

“Attacks targeting UN personnel working to help the Afghan people are unconscionable and we condemn this act in the strongest possible terms,” Pompeo told reporters at the State Department.

An Afghan government spokesman said on Sunday that one foreign nationals had been killed and five others wounded when a grenade was thrown at a UN vehicle in the Afghan capital.