Two men have been arrested in connection with the death of Japanese doctor Tetsu Nakamura, according to security officials in the eastern province of Nangarhar.
Dr Nakamura died after being gunned down in an attack on his vehicle in eastern Afghanistan last week along with five Afghan guards and colleagues as they were travelling to the capital city of Jalalabad in Nangarhar province.
The 73-year-old Japanese doctor, whose long career as the head of the NGO Peace Japan Medical Services, was dedicated to helping some of Afghanistan's poorest people since the 1980s, and was involved in reconstruction work in irrigation and agriculture in the country.
The gunmen had fled the scene and no group has yet claimed responsibility, according to Sohrab Qaderi, a member of the provincial council in Nangarhar. The Taliban, locked in new peace talks with the United States, condemned the attack.
Afghan President Ashraf Ghani on Saturday led a memorial bidding a final farewell to Dr Nakamura and joined Afghan soldiers in carrying Dr Nakamura’s coffin, which was draped in an Afghan flag.
The physician’s wife, Naoko, and daughter Akiko, were among those who attended the ceremony at Kabul airport. They had travelled to Afghanistan, along with three of his colleagues, to accompany his body home to Japan.
A plane carrying his body landed at Narita airport near Tokyo with Naoko and Akiko on Sunday. Japanese Vice Foreign Minister Keisuke Suzuki and other attendants, including his wife, offered a silent prayer at the airport after placing bouquets on his casket wrapped by a white sheet.
Dr Nakamura's body will be transferred to the western Japanese city of Fukuoka, his hometown, on Monday.
Even in a country inured to brutal violence, the killing of Dr Nakamura, who became an honorary citizen for helping to transform barren expanses of eastern Afghanistan and spent decades caring for the sick, came as a horrifying shock to many Afghans.