WASHINGTON — Austin Tice, an American freelance journalist in Syria who hasn’t communicated with family and colleagues since mid-August, is shown alive and in the custody of armed men in a video posted on YouTube.

In the 47-second clip, headlined "Austin Tice still alive," he’s shown blindfolded and disoriented, mangling an Islamic prayer before crying out, "Oh, Jesus." Masked gunmen who act like militant Islamists surround him, calling out "God is great!" and wearing the baggy traditional outfits of fighters operating in Afghanistan.

The video was posted Wednesday but it escaped notice until early Monday, when a link to it appeared on a Facebook page that appears to support the Syrian government of President Bashar Assad. Tips and other evidence previously gathered by the news organizations to which Tice contributed have suggested that he’s in the custody of the Syrian government.

“Knowing Austin is alive and well is comforting to our family,” Tice’s parents, Marc and Debra, said in a statement they released from their home in Houston. “Though it is difficult to see our son in such a setting and situation as that depicted in the video, it is reassuring that he appears to be unharmed. It is evident that the current events in Syria are challenging and difficult for everyone involved. Our wish is that peace and stability can once again return to the people of Syria and that our eldest son, Austin, will soon be safely returned to our family.”

Tice, 31, whose news articles and photos had been published by McClatchy Newspapers, The Washington Post and other news agencies, last exchanged email with colleagues on Aug. 13. At the time, he was thought to be in the Damascus suburb of Darayya and was expected to travel to Lebanon to meet friends Aug. 19 or 20.

Tice’s editors stressed that there was too little information to draw any solid conclusion from the brief footage other than that he was captured alive — welcome news after so many weeks of silence. Executives at McClatchy and The Washington Post joined Tice’s family in renewing their calls for his swift return.

“Austin Tice is a journalist, risking his life to tell the story of what’s happening in Syria to the rest of the world,” Anders Gyllenhaal, McClatchy’s vice president for news, said in a statement. “We ask in the strongest possible terms for his immediate release.”

“We call on those who are holding Austin to release him promptly, unharmed,” Marcus Brauchli, the executive editor of The Washington Post, said in a statement. “Austin is a journalist who was doing his job. He should be allowed to return to his family.”

State Department spokeswoman Victoria Nuland said Monday that U.S. officials had viewed the video but weren’t in a position to verify its authenticity. “We continue to believe that, to the best of our knowledge ... he is in Syrian government custody,” she said.

The FBI has opened an investigation into Tice’s possible abduction, said the assistant director of the FBI’s Washington office, James W. McJunkin. He declined to elaborate.

Terrorism experts expressed skepticism about the video, saying the production quality, style and method of release don’t match videos typically posted by extremist groups such as al-Qaida or its affiliates.

“There’s so much odd about it,” said Will McCants, a former government adviser on violent extremism who’s the founder of the Jihadica website. “There’s no production level, no title page, nothing to indicate it was an al-Qaida group. This is just a raw clip of footage.”

There’s no time stamp or other clue as to when the video was recorded. Tice is shown with long hair and a beard; in photos he posted on his Facebook page Aug. 3, he’s clean-shaven.

The jumpy, amateurish footage begins with a shot of a slow-moving convoy of three vehicles snaking through hilly scrubland; the location isn’t given. It cuts abruptly to a noisy scene of masked gunmen roughly escorting Tice, who’s wearing disheveled clothing and a black blindfold, uphill to a clearing, where he kneels and attempts to recite a Muslim prayer in broken Arabic. A militant holding what appears to be a rocket-propelled grenade launcher can be seen in the background.

“Oh, Jesus. Oh, Jesus,” Tice says in English, appearing out of breath and frightened and placing his head on the arm of one of his captors.

Murad Batal al-Shishani, a London-based analyst of jihadists who’s monitored extremist groups since the early 1990s, said many aspects of the video didn’t jibe with the communiques that al-Qaida-style extremists typically sent out. The call-and-response rhythm in the cries of “God is great” seems off, he said, and it would be unusual for jihadists to include Tice’s mangled prayer, or to release such a low-quality clip when they’re known for slickly produced videos distributed via their own media wings.

“If it was a jihadi video, they have their own platforms. They wouldn’t release it on YouTube,” Shishani said.

The YouTube user who posted the video hadn’t previously uploaded to the site, suggesting that the account may have been created to disseminate the video. Analysts also pointed out that the captions include English and Arabic, which would be unusual — but not unheard of — for a jihadist group.

The clip was later shared on a Facebook page and Twitter account associated with a group called “the Media Channel for Assad’s Syria,” which echoes the government’s line that opposition rebels are terrorists intent on destabilizing Syria. The group’s tweet reads, “Important, please publish and share our clip on the truth about the disappearance of the American journalist Austin Tice.”

The Facebook page posting asserts that “the American journalist Austin Tice is with the Nusra Front gangs and al-Qaida in Syria,” a reference to Jabhat al-Nusra, a jihadist group that’s part of the opposition forces fighting Assad’s troops. For weeks, U.S. analysts have sounded alarm about the presence of an avowed jihadist group on the battlefield, a development that rattles not only Assad’s regime but also the non-Islamist Syrian opposition and its Western allies.

Jabhat al-Nusra boasts a sophisticated media wing that produces a Twitter feed and videos that are clearly labeled and edited. The group repeatedly has said that any release outside its established platforms should be considered fake, said Aaron Zelin, who researches militants for the Washington Institute for Near East Policy and blogs about them at Jihadology.net.

A typical Nusra video, Zelin said, “would start out with a graphic of the media outlet, then a Quranic verse written out, then a series of videos of attacks or someone reading his last words before going out on a suicide mission, a martyrdom operation.”

McCants, the former government terrorism adviser, echoed that observation.

“Everything about the video is uncharacteristic of a polished al-Qaida group like Nusra,” he said. “It doesn’t mean it wasn’t them, but there’s nothing that points in that direction.”

Tice, a former infantry officer in the Marine Corps, entered Syria in May, crossing into rebel-controlled territory via Turkey and traveling in and around Damascus since late July. He contributed more than a dozen articles to McClatchy and three to The Washington Post, with his own military experience adding nuance and detail to dispatches from the front lines of the civil war. He also freelanced for CBS News, Al-Jazeera English and the Agence France-Presse news agency.

Since Tice’s disappearance, information has emerged from both official and unofficial sources to suggest that government authorities captured him. References to him in pro-regime social media outlets as well as press mentions in Iran, a close ally of the Syrian regime, paint him as a spy.

A Facebook page in the name of Assad, the Syrian president, includes a Sept. 16 entry that referred to Tice as an Israeli agent who’d “infiltrated” the country. An Iranian news portal claimed that Tice was a CIA agent who faces the death penalty after being captured by the Syrian military and held in connection with killing three air force officers. The Syrian government has denied any knowledge of Tice’s whereabouts.

The Committee to Protect Journalists has documented a resurgence in dangers faced by journalists in Syria over the last six weeks, noting Tice’s case as well as the disappearance of two other foreign journalists — Turkish cameraman Cuneyt Unal and reporter Bashar Fahmi, a Jordanian of Palestinian origin — who work for the U.S. government-funded al-Hurra TV channel.

“We are deeply concerned about the fate and safety of U.S. freelance journalist Austin Tice and call upon his captors to disclose his whereabouts and release him immediately,” Robert Mahoney, the committee’s deputy director, said in a statement.