An Mi-8 supply helicopter loaded with the NATO-led International Security Assistance Forces (ISAF) was forced to make an emergency landing shortly after taking off from an ISAF base in eastern Afghan province of Kunar Sunday, killing one soldier and injuring three others, Xinhua quoted an ISAF statement as saying. However, it did not identify the nationality of the victims or the cause of the accident. A spokesman with ISAF press department told Xinhua that the case is under investigation. "We do not know the reason for the emergency landing. Investigation is underway and we would inform the press whenever it is complete," said the official, who did not give his name.