Inmates rioting to press for better facilities in an overcrowded Brazilian jail have beheaded two fellow prisoners and taken two guards hostage, officials said Sunday.

Miguel Llanela, a civilian police officer at the Cascavel state correctional center in the southern city of Parana, also said 80 percent of the facility, which houses 1,400 inmates, has been taken over by prisoners.

"It is a tough situation. Police do control the remaining 20 percent and a negotiator has arrived. But it is hard to know how long this situation will go on for," Llanela said, without giving a number of rioting inmates.

State prison officials told G1 news the prisoners launched a violent push for better food and cleaner facilities.

Brazil currently has more than half a million prisoners and faces severe overcrowding. It is short some 200,000 incarceration spots, according to the NGO Conectas that works on prisoners' rights.