China's top financial officials moved to shore up confidence in the country's tumbling stock market, a rare show of coordinated verbal support as the government tries to prevent the deepest equity sell-off since 2015 from infecting the world's second-largest economy.

The statements from heads of China's central bank, securities watchdog and banking and insurance regulator — which promised measures to help ease financial pressures on companies — underscored the growing sense of panic among investors after the country's $3 trillion stock rout accelerated this week and the yuan slid to an almost two-year low. The call for calm came just hours before Chinese data showed a deeper-than-estimated economic slowdown, and a day after Donald Trump took new steps to escalate a trade war with Beijing.

Chinese shares have tumbled at the fastest pace worldwide this year as concerns about trade tensions and weak economic growth combined with fears of forced selling by investors who pledged more than $600 billion of shares as collateral for loans. The rout has left China's ruling Communist Party with few good choices. If authorities intervene to bail out investors like they did in 2015, it might stop the short-term bleeding but undermine efforts to reduce moral hazard. Doing nothing could jeopardize financial stability and weaken Beijing's hand as it tries to end trade tensions with Washington.