Christian Solidarity Worldwide (CSW) has asked the Chiapas State Governor to take action to protect the rights of families whose land reportedly removed by village leaders in Mariano Matamoros.
CSW said the illegal seizure follows public threats to do so by village leaders after sewage services and water supplies were cut on June 14th.
It says public and private appeals were ignored by the government when it was asked to implement precautionary measures to protect the Protestant minority.
Hostilities towards the group began in May 2012, according to CSW, and include physical attacks, the illegal confiscation of private property and attempts to forcibly convert them to Catholicism.
In January the State Government negotiated and signed an agreement with the victims which included religious freedom guarantees and a promise that all arbitrarily confiscated land would be returned to the rightful owner, but it did not take any steps to fulfil its commitments.
In March, village authorities issued a new decree that prohibited all Protestants from buying or selling in the village.
CSW's Chief Executive Mervyn Thomas said, "It is imperative that Governor Velasco Coello take swift action to avert any further deterioration in the situation in Mariano Matamoros.
"The government's failure to respond in any way to the on-going serious human rights violations taking place, despite ample warning and appeals for help from the victims, is unacceptable.
"We continue to be extremely concerned for the safety and wellbeing of the 84 men and women and 42 children whose access to water and sewage services were cut and who have now lost their primary source of income and a significant food source due to the illegal actions of the village authorities.
"Once again we call on the Chiapas State Government to fully implement the agreements it signed in January to resolve the Mariano Matamoros and a number of other outstanding cases as a matter of urgency, and to set in place policies that ensure that religious freedom is upheld for all."