A prison riot in northeastern Brazil left at least seven dead after a fight between two gangs escalated and led to about 70 people, many visiting family members, being held hostage for several hours.

It's not yet clear if all seven killed were inmates.

Prison officials in Bahia state, where the riot took place, say they negotiated an end to the standoff on Monday and all hostages have been released.

Several people were injured in the uprising — but it's not yet known how many.

The riot began late Sunday in the Feira de Santana regional prison. It's severely overcrowded — holding 1,467 prisoners in a space built for 644.

Prison riots are relatively frequent in Brazil and often involve multiple deaths.