The armed assault in Jalalabad city, the capital of Nangarhar province, was the second deadly incident involving aid workers in recent days and prompted appalled reaction in Afghanistan and internationally.

Tetsu Nakamura, 73, was the head of Peace Japan Medical Services — known as Peshawar Kai in Japanese — and had been working in the region since the 1980s, when he began treating patients with leprosy in Peshawar in neighbouring Pakistan.

A spokesman for Afghan President Ashraf Ghani called Nakamura “one of the closest friends of Afghanistan”.

He “dedicated his life to helping and cooperating with our people”, spokesman Sediq Seddiqi said.

Attaullah Khogyani, a spokesman for Nangarhar’s governor, said Nakamura, who had been shot in the chest, was in the process of being transferred to a hospital in Bagram near Kabul when he died.

Five Afghans were also killed: three of Nakamura’s security guards, a driver and another colleague, Khogyani said.

The attack comes as humanitarian groups are on high alert just days after an aid worker for the UN was killed in a bombing in Kabul.

On November 24, Anil Raj, an American who worked for the UN Development Programme in Afghanistan, died when his vehicle was targeted.