In the Swedish town of Sigtuna, seven Viking tombs were discovered that contained well-preserved skeletons.Archaeologists found the remains of eight people, four adults and four kids, over 1,000 years old inside the tombs. They were most likely Vikings who converted to Christianity.Johan Runer, a project manager at Uppdrag arkeologi (a cultural resource management company), said that the graves are indicative of the Christian character.Similar: Photos: A Viking tomb from the 10th century has been found in DenmarkRuner stated that most of the people were buried flat on their stomachs in an east-west orientation, while people who believed in traditional Viking beliefs in this region of Sweden preferred to be cremated.Also, they found charcoal deposits and partially burned caskets. This suggests that fire rituals were involved at least in four burials.Runer explained to Live Science via email that such phenomena were quite common in Christian Viking period graves but once very rare in Sigtuna.Four tombs had stone cairns on top. One of these tombs was also surrounded by a rock cist (stones placed in a box-shaped shape around it).Runer said that these features were not previously known from the town Sigtuna. He also noted that they are common in early Christian graves located in this region of Sweden, which is about 23 miles (37 km) northwest of Stockholm.Over this tomb were the remains of a stone-cairn. (Uppdrag Arkeologi)Viking tragedyArchaeologists believe that one tomb could hold the bodies of twins.Runer stated that there were two infants seemingly of the same age in one tomb.According to the team, "this grave is the tragic result of a miscarriage that occurred late in a couple of their twins."A number of interesting artifacts were also found in the tombs. Runer stated that one individual was buried wearing a leather belt with fittings made of iron and silver-gilt/copper alloy, and that silver coins were found inside his mouth.He said that coin placement in the mouth of a person is a common practice in Viking period Christian burials in central Sweden. Runer stated that another tomb contained a "beautiful ornated bonecomb" in a case.The tombs were discovered by archaeologists in April as part of a survey of the area where a house was to be built. Archaeologists began excavating the site in May. They are still analyzing the skeletons as well as artifacts. In the fall, an osteologist will examine the well-preserved bones.Similar contentImages: Sparkling photos reveal Viking-age jewelry30 of the most valuable treasures in the world that are still missingPhotos: A Viking warrior is actually a femaleLive Science originally published this article. You can read the original article here.