BEIJING — A massive blast at a chemical factory ripped through an industrial zone on China’s eastern seaboard on Thursday, killing at least 47 people and injuring more than 600, local authorities said.

The explosion around 3 p.m. on Thursday left a crater in the ground, flattened nearby structures and spewed toxic fumes over a vast region that abutted residential areas and schools in Yancheng, a city in Jiangsu province, about 180 miles north of Shanghai.

About 4,000 workers and nearby residents have been evacuated, the Yancheng government said on its Weibo account. Ninety people were in critical condition from the blast, which blew out windows and collapsed roofs in a neighborhood a mile away, according to eyewitness videos.

The blast carried echoes of the massive chemical warehouse explosion in 2015 in the northern coastal city of Tianjin, which killed more than 160 people and sparked an accountability crisis for China’s leaders. In a torrent of outrage following that explosion, Chinese citizens accused local and central leaders of failing to improve the country’s poor industrial safety record and covering up the extent of the devastation.

Videos and photos circulating online on Friday showed thick gray smoke billowing over the Yancheng blast site and children crying with blood on their faces. Some reports and social media posts were quickly censored by authorities, prompting a fresh round of criticism about another possible coverup.

The plant where the blast occurred is owned by Jiangsu Tianjiayi Chemical, a company with a long record of environmental violations over the past three years, according to China’s Securities Daily newspaper. It mostly produces benzene and is among a dozen factories operating in the industrial park.

Police have detained officials from Tianjiayi Chemical, the Yancheng government said.

Local media reported that a kindergarten was less than a mile away from the facility. One 74-year-old eyewitness told The Paper, a Shanghai-based outlet, that he heard two distinct explosions less than a second apart that were so forceful they shattered the windows and buckled the ceilings of the house he was in, one mile from the blast site.

The blast was so violent it was suspected of triggering a 2.2-magnitude tremor in a nearby county that was picked up by China’s earthquake monitors.

Authorities said the raging fire required 192 firetrucks and nearly 1,000 firefighters working more than 14 hours to put it out.

Chinese President Xi Jinping, who is in Rome to sign an agreement bringing Italy into his Belt and Road investment plan, ordered officials to mount an all-out response to the incident while the Chinese cabinet set up an emergency investigation team. The state-run Xinhua News Agency warned local officials in a commentary that they were learning “lessons paid for in blood” because of recent major safety lapses.

Chinese officials have vowed for years to improve the country’s dismal safety record, but high-profile accidents have continued to make headlines. Explosions in Sichuan and Hebei provinces last year killed 19 and 23 people, respectively.

There were 51,000 industrial accidents in 2018, which killed more than 34,000 people, according to official Chinese data.

Liu Yang contributed to this report.