Chinese leader Xi Jinping has built a sprawling security system to prevent violent forces from destabilizing society. A new wave of deadly attacks is putting pressure on officials to expand that surveillance state.

China was stunned this month by its deadliest act of public violence since a string of terrorism strikes rocked the remote Xinjiang region in 2014. Dozens were hospitalized and 35 killed by the bloody car-ramming in Zhuhai city that was the culmination of a spate of violence this year — mostly stabbings — which have sparked nationwide anxiety.

Xi responded to spouts of ethnic violence a decade ago by installing a network of facial recognition cameras, tightening internet controls and expanding a national resident database. Now the ruling Communist Party is calling on its army of local officials to weed out would-be attackers, drawing on the nation’s troves of big data for that mission.