An independent Islamic sect in Russia has kept 20 children living underground for almost ten years, a court heard.

The children, including a 17-year-old who was pregnant, had not been exposed to the natural heat of sunlight. They were part of 70 sect members who appeared to have been held captive underground.

Authorities were digging beneath a three-storey building close to the city of Kazan in the republic of Tartarstan when the sect members were found in their underground cells.

The sect, which is known as the "Fayzarahmanist," was named after its 83-year-old organiser Fayzrahman Satarov.

A Tartarstan TV channel called Vesti reported Satarov declared himself a prophet and his house an independent Islamic state. His followers read his manuscripts and most were banned from leaving their eight-storey underground bunker.

On Satarov's background, the media has learned he was described as a former deputy to a Sunni Islamic cleric in the 1970s.

A criminal investigation had been opened into the sect. Authorities learned Fayzarahmanist practices unconventional way of life. The sect even stops its members from seeking medical assistance or education, prosecutors said.

Prosecutors have warned the sect it will be disbanded if it continues its illegal activities, such as stopping its members from seeking medical assistance or education.

Police suspects child abuse may have been done to the kids, but no arrests have been made. For its part, the court will decide whether the children will be allowed to stay with their parents.

Numerous cults and sects have emerged and flourished in the years since the USSR's collapse in 1991.