The Chinese doctor who tried to warn others about the Wuhan coronavirus has died, according to several state media reports. Li Wenliang, a 34-year-old doctor working in Wuhan, raised the alarm about the novel coronavirus on December 30, posting in his medical school alumni group on the Chinese messaging app WeChat that seven patients from a local seafood market had been diagnosed with a SARS-like illness and were quarantined in his hospital. Soon after he posted the message, Li was accused of rumor-mongering by the Wuhan police. He was one of several medics targeted by police for trying to blow the whistle on the deadly virus in the early weeks of the outbreak, which has sickened more than 28,000 people and killed more than 560. Li was hospitalized on January 12 after contracted the virus from one of his patients, and he was confirmed to have the coronavirus on February 1. On Thursday an official for the World Health Organization expressed sadness at news of Li's death. "We are very sad to hear the loss of Li Wenliang," Dr. Mike Ryan, Executive Director for the World Health Organization's Health Emergencies program, said when asked about the doctor's death during a daily coronavirus press briefing in Geneva. "We should celebrate his life and mourn his death along with colleagues," Ryan added. The death toll and number of people infected by the Wuhan coronavirus continues to grow, with no signs of slowing despite severe quarantine and population control methods put in place in central China. The number of confirmed cases globally stood at 28,275 as of Thursday, with more than 28,000 of those in China. The number of cases in China grew by 3,694, or 15%, on the previous day. There have been 565 deaths so far, all but two of which were in China, with one in the Philippines and one in Hong Kong. Silenced by authorities On the same day in December that Li messaged his friends, an emergency notice was issued by the Wuhan Municipal Health Commission, informing the city's medical institutions that a series of patients from the Huanan Seafood Wholesale Market had an "unknown pneumonia." The notice warned: "Any organizations or individuals are not allowed to release treatment information to the public without authorization." In the early hours of December 31, Wuhan's health authorities held an emergency meeting to discuss the outbreak. Afterwards, Li was summoned by officials at his hospital to explain how he knew about the cases, state-run newspaper Beijing Youth Daily reported. Later that day, the Wuhan authorities announced the outbreak and alerted the World Health Organization. On January 3, Li was called to a local police station and reprimanded for "spreading rumors online" and "severely disrupting social order" over the message he sent in the chat group. Li had to sign a statement -- which CNN has seen a photograph of -- acknowledging his "misdemeanor" and promising not to commit further "unlawful acts." He feared he was going to be detained. "My family would worry sick about me, if I lose my freedom for a few days," he told CNN over a text message on WeChat -- he was coughing too much and breathing too poorly to speak over the phone. He was released by police, but returned to work at Wuhan Central Hospital feeling helpless. He said: "There was nothing I could do. (Everything) has to adhere to the official line." On January 10, after unwittingly treating a patient with the Wuhan coronavirus, Li started coughing and developed a fever the next day. He was hospitalized on January 12. In the following days, Li's condition deteriorated so badly that he was admitted to the intensive care unit, and given oxygen support. He later tested positive for coronavirus. Source