James Foley, 39, was last seen on Thanksgiving Day in the Idlib Province, the same region where NBC correspondent Richard Engel and his team went missing in November. It's unclear if Foley's captors are from the same group.
Foley's family went public with his capture on Wednesday, setting up a website to appeal for his release.
“We want Jim to come safely home, or at least we need to speak with him to know he’s okay,” John Foley, Foley's father, told the GlobalPost. “Jim is an objective journalist and we appeal for the release of Jim unharmed. To the people who have Jim, please contact us so we can work together toward his release.”
Foley headed toward the Turkish border about an hour before he was captured. A Syrian witness told a Turkish journalist men held up Foley's car and forced him into another vehicle, but said there was nothing to identify the captors as either rebel fighters, ransom-seekers, pro-government forces or religious extremists.
Foley, who has also reported from Afghanistan and Libya for the GlobalPost and Agence France-Presse, was captured in April 2011 in Libya and spent 44 days imprisoned there by the government.
GlobalPost CEO Phillip S. Balboni joined the family in calling for Foley's release.
“Over the past nearly six weeks we have been working intensively with many parties in the United States and in the Middle East to secure Jim Foley's freedom so he can return home to his loving family," Balboni said in a statement. "Jim is a brave and dedicated reporter who has spent much of the past year covering the civil war in Syria, believing like so many of his colleagues that this is a very important story for the American people to know more about. We urge his captors to release him."
According to the Committee to Protect Journalists, Syria has become one of the most dangerous places in the world for journalists, with 28 deaths reported in 2012 alone.
Notable deaths of 2014 [PHOTOS]
Soviets call Reagan joke 'dangerous' [ARCHIVE]