“We’re investigating reports that Austin Tice is in custody of Syrian authorities,” Marcus Brauchli, the Post’s executive editor, said in a statement. “If the reports are true, we urge these authorities to release him promptly, unharmed. Journalists should never be detained for doing their work, even – and especially – in difficult circumstances.”

Tice’s parents, Marc and Debra, pleaded for his safe return.

"Austin is our precious son, and we beseech the Syrian government to treat him well and return him safely to us as soon as possible," they said in a statement.

In recent months, Daraya had become a stronghold for the rebels who are battling to topple the government of President Bashar Assad. Syrian government forces began shelling the area in mid-August and then fought pitched battles with rebels there for several days, before the rebels reportedly abandoned their positions late Aug. 24 and Syrian troops entered the city Aug. 25. Hundreds of people died in the violence, though it was impossible to know how many of those were combatants.

Tice, however, apparently had left the area before the fighting began.

A number of foreigners, including at least one other American besides Tice, are believed to be in Syrian custody, according to people familiar with the matter in Damascus and outside of Syria who asked not to be identified because of the sensitivity of the topic. It could not be determined if all the unnamed individuals remain in Syrian captivity.

Tice, a law student at Georgetown University and a former Marine infantry officer, was one of the few foreign journalists to report from inside Damascus as fighting raged in Syria’s nascent civil war. Tice’s reporting drew on his own military background to explain fierce battles between regime forces and guerrilla groups. The opposition forces he traveled with weren’t immune to his scrutiny; Tice reported on their own apparent battlefield atrocities in addition to the bloody setbacks they endured from the better-armed Syrian military.

Apart from McClatchy and The Washington Post, Tice also contributed to CBS News, Al Jazeera English, the Agence France-Press news agency and the MCT Photo Service.

Tice was keenly aware of the dangers he faced, he wrote in a posting on his Facebook page, but he implored his friends and family to “please quit telling me to be safe.” He wrote that he drew inspiration from Syrians in the throes of conflict, and that “coming here to Syria is the greatest thing I’ve ever done.”