The provincial Department of Culture and Sports said on October 12 that the jars and several pottery fragments were found at a construction site in Hoa Lu Ward.
At around 2 pm on October 11, Do Van San's family uncovered the objects about 30 centimetres below the surface of a field while preparing the foundations for their house.
The family retrieved and cleaned some of the objects before notifying local authorities. Officials from the Ninh Binh Museum subsequently visited the site and took custody of six pottery jars and several fragments.
A further survey on October 12 at the Cua Bac 2 resettlement area in Hoa Lu Ward found that the jars had been arranged in two east-west rows across an area measuring about 2.2 metres long and 0.45–0.5 metres wide.
The jars were stacked in three staggered layers. Most were placed upside down, while some were arranged with their openings facing each other.
An examination of the surrounding area found no additional artefacts or traces of ancient structures. The jars contained only soil.
Museum experts identified two types of jars, one with straight sides and the other with rounded shoulders. Some featured incised and combed patterns. All were made from fine stoneware fired at high temperatures.
The museum said the jars were household items dating from the Tran Dynasty, which ruled Vietnam during the 13th and 14th centuries.
Their deliberate arrangement suggests they may have been buried for safekeeping, although their original purpose remains uncertain.
The museum has proposed transferring all the objects to its collection for preservation and further research under Vietnam's cultural heritage regulations.
Local authorities and residents have also been asked to report any additional discoveries during construction work.