The authorities have asked for a 30-year prison sentence if Mr Fernandez is convicted. He denies the charges.

As many as 100 people are reportedly still missing after the recent violence, the scale of which prompted the president to send in troops to secure Cobija.

The violence subsided and the blockades were lifted as the two sides began negotiations, but many opponents of the government simply do not believe the president, our correspondent says.

They blame the government and its indigenous supporters for instigating the violence, he adds.