HARBIN - Items testifying the crimes committed by the notorious Japanese germ warfare unit, Unit 731, are being exhibited for the first time in Northeast China's Heilongjiang province.

The exhibition includes 113 items, more than 550 photos and 150 sets of archives. Most of the 113 items were discovered at the site of one of the unit's key buildings, which was the core area dedicated to the unit's bacteria tests and human experiments. Unit 731 demolished the building in August 1945, when Japan announced its surrender in World War II.

The exhibition began on Thursday in the Exhibition Hall of Evidence of Crimes Committed by Unit 731 of the Japanese Imperial Army and will last about three months.

"The items on display are irrefutable proof of the crimes committed by the Unit 731," said Jin Chengmin, curator of the exhibition hall. "The items supplement and complete the evidence chain for the bacterial development, human experiments and germ warfare preparations carried out by Unit 731."

Unit 731 was a top-secret biological and chemical warfare research base established in Harbin as the nerve center for Japanese biological warfare in China and Southeast Asia during World War II.

At least 3,000 people were used for human experiments by Unit 731, and more than 300,000 people in China were killed by Japan's biological weapons.