Image copyright AP Image caption Mr Fahim was part of the alliance that ousted the Taliban in 2001

One of Afghanistan's two vice-presidents, Marshal Mohammad Qasim Fahim, has died of natural causes aged 57, a government spokesman has said.

The Afghan government has called for three days of mourning, during which flags will be flown at half-mast.

Marshal Fahim was a leader of the Tajik ethnic minority and a former warlord.

He was part of the alliance that ousted the Taliban in 2001 and served first as defence minister, before becoming vice-president in 2009.

President Hamid Karzai's office told the Associated Press news agency that Marshal Fahim died from an illness.

Assassination attempt

The president called Marshal Fahim a true patriot and said his death was "a huge loss for Afghanistan".

He was an ally of leading anti-Taliban fighter Ahmed Shah Masood, who was killed two days before the 9/11 attacks by two Tunisian Islamist militants posing as journalists.

After Mr Masood's death, Marshal Fahim headed the Northern Alliance and analysts say he commanded great loyalty from former fighters.

Before the 2009 presidential election, Marshal Fahim survived an assassination attempt when the convoy he was travelling in was fired at with rocket-propelled grenades and machine guns. The Taliban said it carried out the attack.

His death comes ahead of presidential elections on 5 April to replace Mr Karzai, who cannot run for a third term in office.

Marshal Fahim's loyalties had swung between different candidates, Davood Moradian, the head of the Kabul-based Afghan Institute for Strategic Studies, told Reuters.

Presidential candidate Hedayat Amin Arsala told AP Marshal Fahim's death "will affect the future political development". He did not give further details.