SEOUL (Reuters) - North Korea has detained a U.S. university student, the third western citizen known to be held in the isolated state, for committing a “hostile act” and wanting to “destroy the country’s unity”, it said on Friday. 
 
 Otto Frederick Warmbier, 21, of the University of Virginia, was in North Korea for a five-day New Year trip and was detained at Pyongyang airport on Jan. 2 ahead of a flight back to China, said Gareth Johnson of Young Pioneer Tours, which organized the visit. 
 
 According to the North’s official KCNA news agency, Warmbier entered North Korea as a tourist and “was caught committing a hostile act against the state”, which it said was “tolerated and manipulated by the U.S. government”. 
 
 The U.S. State Department, in a statement, said it was aware of reports that a U.S. citizen had been detained in North Korea but gave no other details, citing privacy concerns. 
 
 U.S. Rep. Brad Wenstrup, whose district includes the area where Warmbier went to high school, tweeted on Friday that his office was asking the State Department “to assist however possible in getting Mr. Warmbier home.” 
 
 Further official comment was not immediately available as U.S. government offices were closed ahead of an impending blizzard. 
 
 Johnson said China-based Young Pioneer Tours was in contact with Warmbier’s family and U.S. officials. 
 
 “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,” Johnson told Reuters. 
 
 The Swedish Embassy represents U.S. interests in North Korea. 
 
 KCNA said Warmbier had entered the country with an “aim to destroy the country’s unity”. It did not elaborate. 
 
 According to his social media profiles, Warmbier is from Cincinnati and is an Echols Scholar, awarded to the top 7 percent of incoming first-year students at the University of Virginia, where he majors in economics with a minor in global sustainability. 
 
 Warmbier has also visited Cuba, Ireland and Israel, according to his Facebook profile. 
 
 Warmbier was detained four days before North Korea conducted its fourth nuclear test in violation of UN sanctions, which drew condemnation from its neighbors and the United States. 
 
 A friend and former high-school classmate of Warmbier, who wished to remain anonymous, told Reuters: “Otto is a wonderful, warm person who should never have to go through anything like this. ... The idea that any of this happened is crazy.” 
 
 Calls to the Warmbier home in Cincinnati, Ohio, were not immediately answered on Friday and nobody answered when a Reuters reporter knocked on the door of the house. 
 
 South Korea warned that the United States and its allies were working on further sanctions to inflict “bone-numbing pain” on North Korea after its latest nuclear test, and urged China to do its part to rein in its neighbor. 
 
 North Korea has a long history of detaining foreigners, and the U.S. and Canadian governments advise against travel there. 
 
 Pyongyang has in the past used detained U.S. citizens to extract high-profile visits from the United States, with which it has no formal diplomatic relations. 
 
 While the vast majority of tourists to North Korea are from China, roughly 6,000 westerners visit the country annually. Most are adventure-seekers curious about life behind the last sliver of the iron curtain, and ignore critics who say their dollars prop up a repressive regime. 
 
 Warmbier was on Young Pioneer’s “New Year’s Party Tour,” which, according to the itinerary on the company’s website, was to include watching fireworks in Kim Il Sung Square in the heart of Pyongyang, and an optional helicopter ride. 
 
 A South Korean-born Canadian pastor was arrested in North Korea last year and given a life sentence for subversion. This month, a Korean-American told CNN in Pyongyang he was being held by the state for spying. 
 
 In 2014, Pyongyang released three detained Americans. Last October, it freed a South Korean national with a U.S. green card after holding him for six months. ||||| Image copyright Facebook 
 
 North Korea says it has arrested a US student accused of committing a "hostile act" against the state. 
 
 State news agency KCNA identified him as University of Virginia student Otto Frederick Warmbier. 
 
 He had entered North Korea as a tourist with the intention "to destroy the country's unity", said KCNA, which added that the US government had "tolerated and manipulated" him. 
 
 It did not give further details, but said he was now under investigation. 
 
 The US State Department is "aware of media reports that a US citizen was detained in North Korea" and is working with its protecting power, the Swedish Embassy in Pyongyang, Deputy Spokesperson Mark Toner said. 
 
 He said that no further information would be shared at this time due to privacy concerns. 
 
 North Korea sometimes uses the detention of foreigners as a means of exerting pressure on its adversaries. 
 
 Image copyright AP Image caption The incident follows escalating tensions with rivals including the US and South Korea 
 
 Detained on tour 
 
 China-based tour agency Young Pioneer Tours released a statement confirming that Mr Warmbier had been detained while on one of their tours in Pyongyang, and said his family had been informed. 
 
 It had earlier told Reuters that Mr Warmbier was arrested on 2 January. 
 
 "We are in contact with the Swedish Embassy... who are working with the Ministry of Foreign Affairs to address the case. We are also assisting the US Department of State closely with regards to the situation," it said in the statement. 
 
 "In the meantime we would appreciate Otto's and his family's privacy being respected and we hope his release can be secured as soon as possible." 
 
 Sweden represents US interests in North Korea as Washington and Pyongyang do not have diplomatic relations. 
 
 Image copyright KNS/AFP/Getty Images Image caption Canadian pastor Hyeon Soo Lim is also being held by North Korea 
 
 Mr Warmbier, listed by the University of Virginia's directory as an undergraduate commerce student, is the third Westerner known to be held in North Korea. 
 
 Hyeon Soo Lim, a Canadian pastor of South Korean origin, was sentenced to life imprisonment in December for an alleged plot to overthrow the government. 
 
 A Korean-American is also thought to be in North Korean detention on charges of spying. 
 
 The latest incident comes amid escalating tensions, after the North said it had successfully tested a hydrogen bomb. The claim has not yet been confirmed. 
 
 South Korea has resumed propaganda broadcasts over the border, while the North has been dropping propaganda leaflets on the South. 
 
 The United States is leading calls for new UN economic penalties against the North in the wake of the nuclear test. 
 
 The state department strongly advises Americans against travelling to North Korea. 
 
 In 2014, North Korea released three Americans it was holding in detention - Matthew Todd Miller, Kenneth Bae and Jeffrey Fowle. ||||| Story highlights Detained student was a high school salutatorian, CNN affiliate reports 
 
 Otto Frederick Warmbier is a student at the University of Virginia 
 
 A Chinese travel company says Warmbier was detained January 2 in in Pyongyang 
 
 (CNN) A University of Virginia college student from Cincinnati has been detained in North Korea after being accused of a "hostile act" against the government there. 
 
 Otto Frederick Warmbier was detained January 2 in Pyongyang, according to Young Pioneer Tours, the China-based travel company that organized his trip. 
 
 He was detained at Pyongyang Airport as he was going through customs, the tour company said. 
 
 The company's website says it "provides budget tours to destinations your mother would rather you stayed away from." 
 
 North Korean state media said Warmbier, who reportedly entered North Korea on a tourist visa, is accused of carrying out "a hostile act against the DPRK," referring to the Democratic People's Republic of North Korea.
– North Korea says it has detained an American student from the University of Virginia who visited the country as part of a "New Year's Party Tour." A rep for Chinese travel company Young Pioneer Tours says undergraduate commerce student Otto Frederick Warmbier, 21, was arrested at Pyongyang airport on Jan. 2 after a five-day tourist trip. North Korea's official news agency says he visited with the "aim to destroy the country's unity" and "was caught committing a hostile act against the state," which was "tolerated and manipulated by the US government," per Reuters. The US Embassy in Seoul says it's aware of Warmbier's arrest, per CNN. The tour group says it's working with the State Department and the Swedish Embassy in Pyongyang, which represents US interests there. "We would appreciate Otto's and his family's privacy being respected and we hope his release can be secured as soon as possible," a rep tells the BBC. Reuters notes about 6,000 westerners travel to North Korea each year; the "New Year's Party Tour" Warmbier was participating in promised a fireworks display in Kim Il Sung Square. One other American citizen is being held in North Korea. Kim Dong Chul, who says he's a naturalized US citizen who used to live in Virginia, was arrested in October.