Researchers have found archaeological evidence that early people in the northern mountainous Cao Bang province were in contact with people in the coastal region, according to a source from the Vietnam Archaeological Institute.

"There is concrete evidence of exchanges between early peoples in the mountainous and coastal areas," the head of the excavating team, Trinh Nang Chung, told the English language daily Vietnam News, noting that the team had found seashells (Cyprea arabica) in Nguom Vai cave in Thong Nong district.

The researchers believe the cave was inhabited by people of the Hoa Binh-Bac Son cultures 8,000-9,000 years ago.

The cave, located about 40m above the present inter-districts road, faces northwest and overlooks a large valley with the Ban Gai River running nearby. It covers an area of 500sq.m and is divided into two rooms with a lot of sunlight.

The team dug a hole of 20sq.m in the middle of the cave and found various traces at a depth of 50cm throughout the cave but mainly near its entrance.

"At a depth of 1.3m, we also found fragments of skulls of some of these early residents," Chung said. "In the middle of the cave, some large stones have fallen from the cave's ceiling to lie on top of part of the subject layer, which suggests that early people experienced some strong earthquakes."

The team unearthed a total of about 2,000 objects, including sharpened axes and other tools for chopping, beating, cutting and scraping.-VNA