GENEVA — Officials say a Syrian Arab Red Crescent volunteer and three of six Red Cross staffers taken hostage in Syria are free and safe.

Robert Mardini, the International Committee of the Red Cross' head of operations for the Middle East, said on Twitter that the four were released "safe and sound."

The ICRC's Geneva office confirmed the tweet was accurate, but provided no more details Monday.

Gunmen abducted the seven on Sunday after stopping their convoy in northwestern Syria.