The Shenzhen component plunged 9.03 percent in the opening minutes while the Shenzhen composite fell 8.8%. The Shanghai composite opened at 2,716 points, a drop of 8.6 percent from when trading closed.
The People's Bank of China preempted this by announcing Sunday that it will inject 1.2 trillion yuan (about $173 billion) into the market to offset trade losses amid an ongoing coronavirus outbreak and related quarantine measures.
Cancelled flights, shuttered businesses, and millions refraining from regular consumer activity have spread fears of an economic meltdown in global markets.
Wall Street posted its first monthly loss since August on Friday as US markets began to feel the pinch of a China on virtual lockdown.