hotel got infected two weeks ago after disinfecting the rooms of travellers who tested positive upon arrival in china the virus quickly spread to coworkers while another chain of transmission may have brought it from the airport to local communities many of the early cases were caused by a subtype of the delta strain yet the viruss subsequent spread hasnt been fully accounted for enabling it to covertly fan out across the city and triggering the sweeping lockdown in an effort to contain it more than 200 cases have been detected through thursdaywhile the number of infections remains small the fact they are scattered across the citys 14 districts shows how difficult it will be to contain the outbreak officials still havent identified some chains of transmission and the city is initiating a third round of mass testing in hopes of spotting them subsequent cases have been found in two other cities in the shaanxi province where xian is the capital infections also occurred in beijing and the southern chinese manufacturing hub of dongguan where two dozen cases linked to the xian outbreak were detectedon chinas social media some people described the outbreak as the worst the city has encountered videos posted online show people fighting over food and other essential goods in supermarkets as they stock up for the lockdown entrance examinationthe outbreak comes as the city is set to hold a graduate school entrance examination for some 135000 people next weekend some have been told to sit for the exam in other cities or provinces while those who are infected or have been identified as a close contact will take the test in quarantine meanwhile china has found four omicron infections from people returning from overseas it hasnt yet seen the far more infectious strain spread in the local community authorities have vowed to tighten restrictions at borders and ports as they see a mounting risk of infection seeping in from overseas