LA PAZ, Bolivia (AP) — Three of five Bolivian engineers working for a Canadian mining company were released on Friday by Quechua Indians who had seized them to press their opposition to a planned open-pit silver mine, a relative of one of the engineers said.

“I’ve been informed extra-officially of the release of the hostages and I am going to meet my brother,” the sister of one of the three, Adrian Fernandez, told Bolivision TV.

However, other media reports suggested the engineers, seized on Monday, may have escaped. The three were taken by Bolivian authorities to the nearby regional capital of Oruro, said Fernandez.

The three gained freedom a day after a Quechua Indian was killed and six people injured in a clash with police in a region of Bolivia’s arid and remote southern highlands where Quechua Indians live in relative autonomy.

The fate of two other engineers working for South American Silver was not immediately known.

Nor was it clear exactly how the civilians killed Thursday died.

A local Quechua leader said he suffered a gunshot wound. But Interior Minister Carlos Romero told reporters preliminary reports indicate it was mishandling of dynamite.