An indigenous leader and four other people have died in the violence, according to the public defender's office. The President's office said two people died.
At the cultural centre, one captive officer was forced to drape a national flag around his shoulders and don a hat of a style worn by some indigenous people. The lone female officer in the group was seen wiping away tears.
All were forced to remove their boots in front of hundreds of demonstrators, some holding white roses in tribute to people who have been killed in the unrest. The police officers appeared to be unharmed, and were checked by medics.
"With the blood of our brothers, we won't negotiate," indigenous leader Jaime Vargas declared in a speech to the crowd. He accused the Government, which has floated agricultural aid and other incentives for indigenous groups as a way to resolve the crisis, of deceiving and neglecting Ecuador's poor.
Jose Briones, secretary general of the President's office, said protesters must release all people they "kidnapped" before any dialogue with the Government can proceed.
He also said order was being restored nationwide and that more than 70 per cent of Ecuador's cities were peaceful.
Indigenous protesters are playing a key role in the opposition to the Government, as they have done in the past because of their traditional grievances as a minority.
The announcement by the public defender's office that one of those killed was an indigenous leader seemed certain to inflame tensions.
- AP