Two tombs dating to AD100-200 have been discovered in Hanoi 's Dong Ngac Commune, the Vietnamese Association of Archaeology said.

Building workers unearthed a tomb 2m below ground by chance on April 1. They immediately reported the find to local authorities.

When archaeologists started excavating the site they discovered a second smaller tomb dating back to the 4th-6th century.

After days of digging, archaeologists unearthed numerous artefacts, such earthenware bowls, dishes, jars and pots.

The tombs were constructed from brick, without the use of cement. The bricks in the larger tomb bore round and lozenge designs, while those in the smaller tomb were carved with fishbone-shaped patterns.

Associate Prof Nguyen Lan Cuong, deputy secretary general of the archaeology association, said the bricks bore ornate pictograms, thought to represent the name of the builder.

"Research on the tombs will help us understand more about the period and the tomb-building technique, as well as the life of the people at that time," Cuong said.

He said excavation of the site would continue for the foreseeable future. "However, I don't expect to find human remains because they would have decayed," Cuong said.

Building work will resume once the site is fully excavated, he added./.