China's top security agency has called for a crackdown on "hostile forces" after rare protests against Covid rules in Chinese cities at the weekend. Police officers have flooded now-empty protest sites, with some protesters saying police have contacted them to seek information on their whereabouts. Meanwhile the country's health officials say lockdowns should be "imposed and eased quickly". China has recorded record numbers of new cases in recent days. It is the only major economy with a zero-Covid policy, with local authorities clamping down on even small outbreaks with mass testing, quarantines and snap lockdowns. Over the weekend, thousands in China took to the streets demanding an end to the strict measures - with some even making rare calls for President Xi Jinping to stand down. But a heavy police presence in China's major cities, including Beijing and Shanghai, seems to have curbed further protests on Monday and Tuesday. The ruling Communist Party's Central Political and Legal Affairs Commission, which oversees domestic law enforcement across China, said it was "necessary to crack down on infiltration and sabotage activities by hostile forces in accordance with the law". The statement, reported by Chinese news agency Xinhua, did not mention the recent demonstrations, which began after a fire in a high-rise block in Urumqi, western China, killed 10 people on Thursday. Many Chinese believe Covid restrictions in the city contributed to the deaths, although the authorities deny this. Police officers were seen on Tuesday patrolling in large numbers in parts of Beijing and Shanghai where demonstrations were held at the weekend. There were also reports of around 150 officers showing up at a busy shopping area in the southern city of Shenzhen after rumours of a planned protest there circulated on social media. Also on Tuesday, Chinese health officials said the authorities would work to reduce "inconvenience" caused by the Covid pandemic. Mi Feng, spokesperson of China's National Health Commission (NHC), told reporters that lockdowns should be "imposed and eased quickly" and that "excessive control measures should be continuously rectified". Health officials earlier called for more targeted Covid measures - saying complaints over tough curbs were a result of the "arbitrary" local roll-outs, rather than national guidelines. In southern Guangdong province, authorities announced changes to local Covid policy on Tuesday evening, allowing some close contacts of Covid cases to quarantine at home rather than in state facilities. Elsewhere, the UK has summoned the Chinese ambassador for a meeting after a BBC journalist, Ed Lawrence, was beaten and briefly detained while covering anti-government lockdown protests on Sunday. — BBC