At least 15 people have been killed after violent clashes erupted in a prison in the Brazilian state of Amazonas on Sunday.
Officials said clashes broke out around 1500 GMT during visiting hours at the facility.
An investigation into the incident is currently underway, with officials adding that "there had never been deaths during the visits".
Senior officials said their speedy reaction helped reduce the fatalities.
In 2017, the prison was the scene of an inmate uprising that ended with 56 dead.

Netanyahu says Israel to decide which international forces in Gaza acceptable
Two suspects in Louvre jewel heist case arrested in Paris
Russian attack on Kyiv kills three, injures 31
PKK announces withdrawal from Turkey
Israeli military says it conducted 'targeted strike' in central Gaza
