Tlalnepantla – A riot and fire erupted late on Monday at a prison in a Mexico City suburb, prompting authorities to send in hundreds of police and firefighters to restore order. The fire was extinguished and there were no reports of casualties at the Barrientos prison, located in the municipality of Tlalnepantla, officials said.Some 150 relatives of inmates, some in tears, stood near the prison awaiting for news while police officers cordoned off the area."I want to tell the families of the inmates that they have nothing to worry about, [the riot] was controlled with minimal effort," State of Mexico security chief Eduardo Valiente said after visiting the prison.Jose Manzur, general secretary of the State of Mexico government, said there were no reports of serious injuries or deaths.Manzur told Uno TV that the riot was the result of a "dispute between groups" of inmates, and that 600 police officers entered the prison to restore order.Local media showed images of flames coming out of the prison. The chaos cause panic among relatives of inmates who flocked to the prison.A woman named Dolores, who declined to give her last name, told other relatives of inmates that she had spoken with the prison's director, who assured her that some just had "scrapes and bruises" from punches.It is the latest unrest to hit a Mexican prison.In February, 49 inmates were killed in a massive brawl at the Topo Chico prison in the northern city of Monterrey. Three others were murdered earlier this month at the same prison.A report by the National Human Rights Commission found that inmates govern themselves in 71 state prisons, which are also overcrowded.