Four US university tutors are in hospital after they were stabbed by an unknown assailant at a public park in China. The Iowa Cornell College instructors were injured in a "serious incident" during a daytime visit to the park in Jilin province, northern China, a college statement said. Iowa Representative Adam Zabner said his brother, David, was one of the four injured in the incident, which he described as a stabbing. He said the group had been visiting a local temple on Monday when they were attacked by a man with a knife. Zabner said his brother had been stabbed in the arm at Beishan Park and was recovering in hospital. "He has not yet been released this morning but he's doing ok," he told CBS News. A US State Department spokesperson told the BBC they were aware of reports of a stabbing incident in Jilin, but could not provide more information. Cornell College said the four instructors had been teaching "as part of a partnership with a university in China". The group had been accompanied by a member of Beihua University at the time of their visit to the park on Monday. Chinese authorities are yet to respond on the incident, however, images of the aftermath were quickly shared on social media. Images circulating appear to show at least three people bleeding and lying on the ground. However, the incident appears to have been quickly censored on China's internet. On Tuesday, searches for terms such as "foreigners Jilin" produced no results despite the search term trending on Weibo. Internet users instead resorted to discussions under adjacent topics while some were also seen asking for more information about the incident. There have also few reports about the incident in Chinese state media. Zabner said his brother, a Tufts University doctoral student, had visited China before and was on his second trip to the country with Cornell College. Amid tense diplomatic relations, Beijing and Washington have sought to re-establish people-to-people exchanges in recent times. Chinese President Xi Jinping has unveiled a plan to invite 50,000 young Americans to China in the next five years, while Chinese diplomats say a travel advisory by the US State Department has discouraged Americans from going to China. — BBC