The Taliban have claimed responsibility for downing a Black Hawk helicopter in southwestern Afghanistan on Thursday.

A Taliban spokesman announced on Thursday evening that "Taliban fighters shot down a helicopter and killed all its passengers in Khanashen Dewalak area near Garmsir in the southern Helmand province," CNN reported on Friday.

The US-led International Security Assistance Force (ISAF) and Afghan officials confirmed on Friday that the helicopter’s four crew members, all of them American, are dead.

On Thursday, an ISAF official had said that the crash had occurred due to “bad weather.”

This comes days after the Taliban said they had targeted an unmanned US reconnaissance aircraft in Afghanistan's eastern province of Laghman, on April 14, as it was performing a mission to collect information in the area.

The claim came on the same day as Afghan provincial security chief Sayed Amir Shah Sadat said an American spy drone had crashed in the Ghazni Province in eastern Afghanistan.

The rising number of military casualties in Afghanistan has caused widespread anger in the US and other members of the Western military alliance, NATO, undermining public support for the US-led war.

According to figures released by the independent website, icasualties.org, a total of 120 US-led troops have lost their lives in the violence-hit country so far this year.