A global team of scientists led by the World Health Organization arrived in China's central city of Wuhan, where COVID-19 first surfaced in late 2019, to investigate the origins of the pandemic, state television said on Thursday, according to Reuters. The team will spend about a month in the city, including two weeks in quarantine. Scientists suspect the virus that has killed 1.9 million people since late 2019 jumped to humans from bats or other animals, most likely in China's southwest. China rejected demands for an international investigation after the Trump administration blamed Beijing for the virus's spread. The members include virus and other experts from the United States, Australia, Germany, Japan, Britain, Russia, the Netherlands, Qatar and Vietnam. A government spokesman said this week they will "exchange views" with Chinese scientists but gave no indication whether they would be allowed to gather evidence. They will undergo a two-week quarantine as well as a throat swab test and an antibody test for COVID-19, according to a post on CGTN's official Weibo account. They are to start working with Chinese experts via video-conference while in quarantine. Meanwhile, two members of the team were blocked from flying to China from Singapore after "they tested positive for IgM antibodies", the WHO said in a tweet. IgM antibodies are among the earliest potential signs of a coronavirus infection, but could also appear in someone who has been vaccinated or previously infected (but is no longer a carrier) of the virus. False positives are also possible with such tests. Since November 2020, travelers flying into China have to show negative results for an IgM antibody test, and a PCR test, before they will be allowed to enter. — Agencies