India, Nov. 30 -- China on Tuesday further strengthened police presence in cities, tightened online censorship and arranged to send university students home as authorities tried to prevent protests by people exasperated by hard Covid-19 curbs. Reports said police were digging up records of individuals who were part of weekend protests and summoning them to police stations while others at protest sites were asked to show phones for messages related to the demonstrations. China's social media platforms were being gradually scrubbed clean of even indirect references to the protests, which took place in several cities including in Beijing, Shanghai, Urumqi, Guangzhou, Wuhan and Hangzhou. P10...