"Unfortunately, there's no news yet on our two colleagues unaccounted for," Thomas Glass, a spokesman for the International Committee of the Red Cross (ICRC), told AFP.

"We are actively trying to locate them."

No militant group has so far claimed responsibility for the killings, but Jowzjan's police chief Rahmatullah Turkistani has blamed local Islamic State jihadists.

The attack underscores how aid workers in Afghanistan have increasingly become casualties of a surge in militant violence in recent years.

It comes at a time when Afghanistan is in dire need of humanitarian assistance, with more than 100 people killed in recent avalanches and tens of thousands displaced by the wrenching conflict.

The ICRC, which has been working in Afghanistan for three decades, said it was putting its nationwide operations on hold, but there were no plans for now to withdraw staff.

The Taliban, the largest militant group in Afghanistan which promptly distanced itself from the attack, has assured ICRC of security in areas under their control.

"The (Taliban) calls on the officials of ICRC to refrain from suspending their services as the Afghan nation is (in) need of humanitarian aid and health services more than ever before," the group said on their official website on Thursday.

source: AFP