The bodies of seven people have been found in a mass grave in an indigenous area of Panama controlled by a religious sect.The deceased include a pregnant woman and five of her children.Authorities believe that a religious sect performed an exorcism on the victims in the Ngäbe-Buglé region in the north-west of Panama. A further 15 were freed from alleged captivity.Ten people have been arrested on suspicion of murder.Prosecutors announced on Thursday that they were investigating the case.Senior prosecutor Rafael Baloyes said the grave was discovered after locals alerted authorities last weekend about several families being held against their will by an indigenous-run church.The area the bodies were found is a remote area about 250km (155 miles) from Panama City. It is controlled by a religious sect called the New Light of God.Mr Baloyes said: "They were performing a ritual inside the structure. In that ritual, there were people being held against their will, being mistreated. All of these rites were aimed at killing them, if they did not repent their sins.The 15 people rescued suffered bodily injuries, a police official confirmed.The suspects, which include a minor, are expected to appear in court on Friday or Saturday.A source close to the investigation told AFP news agency that one of those arrested is the father of the pregnant woman found in the grave.