The northeastern city of Harbin will enact a new law to stop the demolition of the remains of the Unit 731 complex in a bid to strengthen the preservation of the world's largest biochemical weapon research center used by Japanese forces during the invasion.

The law, which will soon be reviewed by the city legislature, will impose fines and penalties for any damaging act to the remaining structures, which are mostly scattered in the Pingfang District in the capital of Heilongjiang Province.

The law will also add newly discovered sites to the list of protected areas.

Japanese forces built the secret base during the Second World War as a site for conducting biochemical weapons research and notorious live experiments.