A photojournalist and an interpreter for the United States’ National Public Radio, more commonly known as NPR, were killed in Afghanistan on Sunday. David Gilkey, the photographer and Zabihullah Tamanna, NPR’s Afghan interpreter, were on assignment and travelling with an Afghan army unit when it came under attack by unidentified militants. US Secretary of State John Kerry released a statement condoling their deaths.

According to the news organisation, Gilkey was considered one of the best photojournalists in the world, winning several awards for his work on wars in Afghanistan and Iraq. Gilkey took photographs of conflict in Israel and Gaza, the apartheid in South Africa, the Haiti earthquake, the famine in Somalia and the Ebola outbreak in Liberia. Michael Oreskes, NPR's vice president for news, in an email to the company’s staff said, “As a man and as a photojournalist, David brought out the humanity of all those around him. He let us see the world and each other through his eyes.”

Zabihullah had earlier worked as a photojournalist for Chinese agency Xinhua. Before his death, he covered major daily news in Afghanistan. His NPR colleague Philip Reeves said, “He was a lovely man, with a great eye for a story and deep wisdom about his country.”

Afghanistan is one of the deadliest places in the world for journalists. In January, seven staff members from a local television channel died in a car bomb strike. British-Swedish journalist Nils Horner was shot dead in an “execution-style attack” in Kabul in 2014, the last foreign journalist to be killed in the country.