KABUL, June 6 -- A U.S. journalist and his Afghan translator, were killed as militants attacked an Afghan army convoy in the southern Helmand province on Sunday, an Afghan military official confirmed early Monday.

"David Gilkey of U.S. National Public Radio (NPR) and his translator Zabihullah Tamana were embedded a convoy of Afghan national army when the militants fired an 82 mm caliber gun and it unfortunately struck the military vehicle Humvee where the ill-fated journalists were in," Major General Mohammad Moheen Faqir, commander of army Corps 215 Maiwand, told Xinhua.

"Taliban are suspected to carry out this attack since the militant group are active in that area," he added. However, neither group nor individual has claimed responsibility.

"Both the journalists were killed on the spot in the unfortunate incident which occurred in Marja district at around 02:30 p.m. local time," the official added.

The late journalists were covering the clashes between security forces and militants as well as the security situation in the restive Helmand province when the gruesome incident happened, the official said, adding Tamana had served as translator for Gilkey in the mission.

An army soldier who was driving the Humvee used by the ill-fated journalists was also killed in the attack, the official asserted.

Two more NPR reporters were travelling in a separate vehicle escaped unharmed, Faqir said.

Zabihullah Tamana, 38, had served as photojournalist for Xinhua News Agency Kabul bureau from 2003 to 2010.

Around 50 journalists have been killed in Afghanistan over the past one and half decade, six of them since 2015, according to Nai, an agency supporting media in Afghanistan.