The top recruiter for Islamic State's affiliate in Afghanistan was killed in an American drone strike, US officials have confirmed.

Abdul Rauf and seven others were killed when the strike hit their car in the first targeted attack on a leader of IS in Afghanistan.

Officials have expressed concerns about IS seeking recruits in Afghanistan, as US forces withdraw and Afghan forces take control of the country's security.

Although the US is no longer conducting combat operations in Afghanistan, troops there - including special operations forces - are still carrying out counter-terrorism missions.

There are still about 10,600 US personnel in Afghanistan.

The deputy governor of southern Helmand province said earlier this week that Rauf was killed, but US officials awaited further evidence.

During the Taliban's rule, which ended in late 2001, Rauf was a corps commander in the western province of Herat and in capital Kabul. Rauf spent years in the Guantanamo Bay detention centre in Cuba before being released several years ago.