China's top leadership on Friday ordered all-out efforts to search for and rescue victims of a deadly chemical blast in Jiangsu province in which 64 people died and 94 were seriously injured.

Strong measures also were taken to prevent any subsequent pollution. A thorough inspection of high-risk industries was ordered nationwide to root out similar dangers.

The blast occurred at 2:48 pm on Thursday at the Tianjiayi chemical plant in Xiangshui county's Chenjiagang chemical park, and the fire spread to 16 enterprises nearby.

Hospitals treated about 640 people. Among them, 34 were in critical condition and 60 others had severe injuries, rescuers said on Friday.

President Xi Jinping, in Europe on a three-country tour, ordered on Friday all-out efforts to search for anyone who may be trapped by debris. The injured must be treated in a timely way, relief work must be done properly and social stability must be maintained.