SHIJIAZHUANG, Jan. 16 (Xinhua) -- Archaeologists have unearthed another batch of over 20 fossilized mammoth footprints along with other stone tools left by early humans in northern China's Hebei Province.

More than 20 fossilized mammoth footprints dating back around 1.6 million years were found alongside dozens of stone tools and animal fossils at the Nihewan ruins area in 2018, said Xie Fei, a researcher with the Hebei Cultural Relics Institute.

First discovered in the 1920s, the area has seen the excavation of a large number of paleolithic relics dating back about 2 million years.

Xie added it was the first time that fossilized mammoth footprints had been unearthed from the area since 66 such footprints were uncovered between 2001 and 2005.

"The fossilization of mammoth footprints requires strict natural conditions," Xie said. "The new discovery further proves that a large number of mammoths lived in this area for a long time."

As of 2018, more than 380 paleolithic and neolithic relic sites had been discovered at the Nihewan ruins area.