HARBIN - Four artillery shells discarded by Japanese troops around the time of World War II have been found in Northeast China's Heilongjiang province, local police said Tuesday.

The shells, about 18 cm in length, were unearthed 2 meters underground at two construction sites on March 7 and 8 in Qiqihar city's Tiefeng district, said an officer with the district's police station.

Following an investigation, experts confirmed the shells were left by Japanese troops, and they have relocated the shells to a safe site for final destruction.

Qiqihar was the headquarters of the Japanese Kwantung Army's No 516 and No 526 troops equipped with chemical weapons during World War II.

On Sept 18, 1931, Japanese forces attacked the barracks of Chinese troops in Northeast China's Shenyang, Liaoning province, marking the beginning of the Japanese invasion and occupation that lasted 14 years.

After the Japanese army was defeated in 1945, they buried a large quantity of chemicals weapons, shells and bombs underground.