(CNN) -- About 300 indigenous people from eight ethnic groups have released about 100 workers who had been held hostage on the banks of the Aripuana River to protest construction of a hydroelectric dam over what they consider a holy site, Brazilian state media reported Monday.
Government officials were to meet Monday with representatives from the dam and the National Foundation for Indigenous Affairs in the state of Mato Grosso, the state-run Agencia Brasil news service said.
The indigenous people -- who painted their bodies as a declaration of war -- encircled a large area where the Dardanelos hydroelectric dam is under construction in Mato Grosso, Agencia Brasil said.
The Brazilian Indians are asking for reparations for what they claim has been an attack on their sacred land, said Antonio Carlos Ferreira Aquino, local coordinator of the National Foundation for Indigenous Affairs, in an interview with the agency.
"They don't want money in their hands," Aquino said. "What they want is a sustainable program in the area that will recover the loss they have suffered in this archaeological site."
Aquino said the Indians, who took over the land early Sunday afternoon, had not provoked any violence.
Paulo Rogerio Novaes, who is overseeing the construction project of the Dardanelos dam, said he feared for the well-being of the local workers.
"They [the Indians] said that if in two days, no officials appear, they will set fire to all the areas of construction," Novaes claimed.
He told Agencia Brasil that the hydroelectric dam -- which is being built approximately 26 miles from the nearest tribe -- will not affect indigenous lands.
According to estimates from the foundation, there are 33 distinct ethnic tribes and about 25,000 Indians in the state.
Dardanelos dam is expected to supply electricity to 600,000 people daily.
Journalist Helena de Moura contributed to this report.