( CNN ) -- The mother of an Ohio-born man is `` hanging on by a thread '' after her son disappeared earlier this month in violence-wracked Syria , according to family members . Obada Mzaik , a dual American and Syrian citizen , went missing on January 3 after he traveled with his brother on a flight from Detroit to Damascus , his uncle , Dr. Firas Nashef , told CNN . Mzaik was studying civil engineering at a private university in the Syrian capital and had planned to pursue a master 's degree in the United States , his uncle said . The 21-year-old student was born in Columbus , Ohio , but moved with his family back to Syria when he was child . He had enrolled in a seasonal program at a Michigan community college . His uncle said Mzaik returned to Syria earlier this month with his brother , Obaie Mzaik , to visit family and prepare for the start of the new semester in Damascus . The 19-year-old brother said that upon their arrival , they were detained by security officers for questioning , according to Nashef . The younger brother was soon released , but the officers kept Obada Mzaik for further questioning . `` In his mind , he was expecting to see his brother in the morning , '' said Nashef . `` But that never happened . '' Mzaik 's family is now fearing the worst . `` We hear some horrendous stories from over there , '' said Nashef . `` And my sister is hanging on by a thread , '' he said of the missing student 's mother . `` We 're all hanging on with a bit of hope . But she 's angry and she has no information . '' This month 's arrest is n't the first time the 21-year-old has been detained by Syrian security forces . Last summer , he was arrested and held for 37 days for `` spreading fliers about the revolution , '' according to his uncle . A Facebook page , meanwhile , is calling for Mzaik 's release . The U.S. State Department also weighed in Tuesday , saying it 's aware of reports of his disappearance . `` We are working with local authorities to ascertain ( Mzaik 's ) welfare and whereabouts , '' said State Department spokesman Noel Clay . Mzaik is at least the second U.S. citizen to have disappeared this month in Syria , raising questions as to whether the missing men could usher in a more public State Department presence in the restive country . Abdelkader Chaar , 22 , is thought to have been arrested in Aleppo , Syria , five days after Mzaik disappeared . Chaar was born in Syracuse , New York , moved to Aleppo with his parents when he was a boy and is a medical student at Aleppo University , his uncle said . His family has not been told why he was arrested , said Sam Chaar , who spoke to CNN from Arizona . Read more about the arrest of Chaar . The disappearances of both men come as anti-government demonstrations raged throughout the country . Protesters last week focused their attention on political prisoners and demanded the release of detainees . At least 10 people were slain in clashes Friday , according to the Local Coordination Committees of Syria , an opposition activist group . For more than 10 months , Syria has been in the throes of an anti-government public uprising and a brutal security crackdown against protesters . The United Nations last month estimated more than 5,000 deaths since mid-March . Opposition groups estimate more than 6,000 people have died . Also , the Arab League is extending its monitoring mission to see whether the government is adhering to an agreement to end the violence . Arab League extends its mission in Syria . The Arab League has called on President Bashar al-Assad 's regime to stop violence against civilians , free political detainees , remove tanks and weapons from cities and allow outsiders , including the international news media , to travel freely around Syria .
Obada Mzaik , a dual American and Syrian citizen , went missing on January 3 . The year - old boy was born in Columbus , Ohio ; he was in Syria with his brother . He is at least the second American citizen to have gone missing in Syria this month . He 's family back in the United States is now fearing the worst .