Four hostages held by a Brazilian indigenous group have been released in good health, after two days of captivity in northeastern Brazil.

The iron ore mining company known as CVRD (Companhia Vale do Rio Doce) said Thursday its four employees were let go after negotiations were set up between the hostage-takers and Brazil's National Indian Agency, which deals with indigenous issues. The hostage-takers, members of the Guajajara ethnic group, were demanding better public health care.

They seized their hostages Tuesday in northeastern Brazil, after blocking a rail line that carries iron ore and other cargo to an Atlantic Ocean port.

This is not the first time that indigenous groups have taken hostages in Brazil to draw attention to their complaints. In December, ethnic Indians blocked a CVRD railway line, but withdrew after negotiations.

Some information for this report was provided by AFP, AP and Reuters.