KABUL: A Nato soldier and a civilian contractor have been killed in a suspected insider attack in eastern Afghanistan, the latest in a series described by a top US general as “the signature attack” of the Afghan war.

The assault on Saturday night also resulted in Afghan army casualties, NATO's International Security Assistance Force said Sunday, without providing further details.

But police spokesman Abdul Wali told AFP that two Americans had been killed and three were wounded, while three Afghan army soldiers died and two others were hurt.

The deaths followed “a verbal dispute” during a joint operation in Sayedabad district of Wardak province west of Kabul, the provincial governor's spokesman Shahidullah Shahid told AFP.

A joint assessment of the incident by ISAF and the Afghanistan National Army is under way.