Exactly what Warmbier is accused of doing or saying is unknown, and North Korean media have not released any particulars.

Some news reports indicated that Warmbier had been out celebrating the new year the night before the plane was to leave.

“We are in touch with Otto’s family, the U.S. State Department and the Embassy of Sweden in Pyongyang and doing all we can to secure his release,” said Gareth Johnson of Young Pioneer Tours, which organized the five-day New Year’s holiday visit.

Warmbier is an economics major with a minor in global sustainability in the McIntire School of Business. He grew up in Cincinnati and attended Wyoming High School from 2009 to 2013. He was Wyoming High School’s salutatorian in 2013, a spokeswoman for Wyoming City Schools said. School officials met with the Warmbier family Friday. He played soccer while enrolled at the high school and was a gifted player, officials said.

Social media accounts for Warmbier show interests in finance, travel and rap music. He also has visited Cuba, Ireland and Israel, according to his Facebook profile, which has since been taken offline.

Warmbier is an Echols Scholar, awarded to the top 7 percent of incoming first-year students at UVa.