80 Yanomamö murdered by Brazilian miners?

Yesterday we got the news that, according to Horonami, an NGO for the defense of the Yanomamö, 80 of their people were murdered by garimpeiros, illegal Brazilian miners who entered Venezuelan territory - as they so very often do. The NGO asked for a governmental inquiry to take place as soon as possible. The attack, the NGO said, took place on 5 July in Momoi, Alto Orinoco, in the deep jungle.
This is an optimistic view of where the Yanomamö used to live.  Garimpeiros and
other foreigners have been encroaching in their territory

Apparently, three survivors managed to escape and walked all their way to the closest human settlement, which took several days. Still, I am puzzled by the amount of time since that happened and we get the news - it has been almost two months-. Below you can see a little map of the Alto Orinoco municipality. The settlement was in the Upper Ocamo. You can read more details about the whole event and the background from a report presented by a First Nation organisation here.

We haven't any more details. Is it true? I am asking people who have been frequently in Yanomamö territory but I am still waiting for the answer as they are very hard to reach.

I really hope the number of victims is lower. One thing has been clear for a long time already: First Nation organisations have been denouncing for years about the illegal miners who assault the natives, kidnap their women and pollute the rivers with mercury. The Venezuelan government does very little...specially because it doesn't want to bother the Brazilian government...the new master of the region. Brazil has now much more stringent control of its territory and illegal miners prefer to cross over to Venezuela.

Alto Orinoco Municipality, larger than Slovakia or the Netherlands

More information, in Spanish, here