KABUL (Reuters) - A Spanish employee of the International Committee of the Red Cross has been released less than a month after he was kidnapped by gunmen in northern Afghanistan, the aid group said on Sunday.

The staff member, identified by the ICRC only as Juan Carlos, was traveling with three Afghan colleagues between Mazar-i-Sharif and Kunduz on Dec. 19, 2016, when gunmen stopped the vehicles.

The other ICRC staff were immediately released, but Juan Carlos was held for nearly four weeks.

The aid group thanked Afghan authorities and community members who helped secure the man’s release, but would not identify the abductors and their motives, or provide any details on how the employee was freed.

“We are relieved and grateful that Juan Carlos is now back with us, safe and sound,” the head of the ICRC delegation in Afghanistan, Monica Zanarelli, said in a statement. “His abduction was a terrible ordeal for him, as well as for his family, friends and colleagues.”