The southern Chinese city of Shenzhen is launching blanket searches in areas where travellers from Hong Kong are known to congregate in a bid to stop the community spread of Covid-19 . A resident surnamed Liu from the Shatou residential area in Futian district, the heart of Shenzhen, said he had been locked down at home since February 22 after a positive case in his area. The entire area is locked down with food and other living necessities delivered by community staff and residents are only allowed to leave to collect deliveries or take daily nucleic tests, Liu said. He believes that up to 50,000 people have been affected by the measures. Control measures appear to have been tightened in recent days with community staff visiting residents door-to-door every day to check on how many people are inside, making sure the numbers stay the same. Starting on Tuesday, staff also came to his door to conduct tests. “The outbreak is raging [here],” he said. “It feels a bit scary.” According to Caixin Media, a respected business media outlet, residents in Shuiwei, a community about 5km from Shatou, said staff have been checking on homes, with some even looking under beds and in cupboards. The Shatou and Shuiwei communities are close to the Huanggang checkpoint on the Shenzhen-Hong Kong border and it has traditionally been an area that hosts a lot of travellers between the two cities. What Covid-19 lockdown can Hong Kong handle … or is it ready at all? Shatou has been heavily hit by Shenzhen’s latest Covid-19 outbreak. Mass tests are finding new cases there every day despite being locked down for more than a week. On Wednesday, Shenzhen announced 25 new cases, including 16 from Shatou. China announced the detection of a total of 71 local cases, 32 of them in Guangdong province. This compares with 32,597 cases in Hong Kong as of Tuesday afternoon. So far, the Shenzhen authorities have not issued any official explanation for the tightened measures, nor announced the origin of the latest outbreak. In February, Guangdong province tightened measures for stowaways, after some people who had illegally crossed the border from Hong Kong tested positive. Some cities have offered up to 500,000 yuan (US$78,800) as reward for tip-offs about illegal entrants. Meanwhile, Shenzhen has increased patrols and installed new surveillance cameras and searchlights. Coronavirus: US consulate issues travel alert against Hong Kong The city’s current efforts to contain the virus have seen it put more than 40 residential compounds under lockdown, suspend some bus routes, close restaurants, sports grounds and museums, and order residents in various areas to go through daily mass screenings. On Wednesday the city government said the outbreak was gradually being brought under control as most new cases are discovered in close contacts of patients in quarantine or key areas under observation. However, more screenings and measures will be taken in key districts, including Futian, to make sure that no positive case is undetected.