Monterrey, Mexico (CNN) -- Dozens died and 30 inmates escaped during a weekend prison riot in northern Mexico, an official said Monday.
The prison's director and 18 guards have been removed from their positions and are under investigation, Nuevo Leon Gov. Rodrigo Medina told reporters.
"There is no doubt that without the help of prison officials, it would have been very hard to make this escape. ... For us, it is difficult to confirm that the betrayal, corruption and complicity of a few can hinder the work of good police, soldiers and sailors who risk their lives daily for the security of Nuevo Leon's residents," he said.
Authorities are offering a reward of 10 million pesos (about $788,000) for information leading to the escapees' capture, Medina said. Preliminary reports indicate the escapees were members of the Zetas drug cartel, he said.
A fierce rivalry between drug cartels likely fueled the fighting that killed 44 people Sunday inside the prison in Apodaca, Nuevo Leon, state security spokesman Jorge Domene told reporters.
At least two Zetas leaders, including the suspected head of the cartel in the nearby industrial city of Monterrey, were among the prisoners who escaped, according to Mexican military records.
Prisoners could have used the riot to engineer their breakout, Domene said Sunday. He did not say how prisoners inside acquired the clubs, stones and sharp objects they used in the fighting.
Earlier Sunday, Domene said inmates had taken a guard hostage as clashes broke out at the prison. Some prisoners also set mattresses ablaze, sending smoke rising above the facility, he said.
Federal and state police surrounded the prison as anxious family members awaited information outside its gates.
The clashes, which occurred in a part of the prison where most inmates were serving time for federal drug trafficking offenses, might have begun as a fight between the Zetas and Gulf cartels, Domene said.
The Zetas started with deserters from the Mexican Army and quickly gained a reputation for ruthless violence as the armed branch of Mexico's Gulf cartel. The partnership ended in 2010, and turf battles between the rival cartels are common in northern Mexico.
State officials have asked Mexico's interior ministry to transfer inmates connected with federal offenses out of the prison, which has become significantly overcrowded as authorities crack down on organized crime, Medina said Monday.
The Apodaca prison was housing about 3,000 prisoners at the time of Sunday's riot, Domene said Sunday.
Last year, 14 inmates were killed and 35 people were injured in a fire in the prison's psychiatric ward.
Nearly half of Mexico's 428 penitentiary centers are overcrowded, according to federal police statistics.
After more than 350 people died in a fire in a Honduran prison last week, a United Nations official said widespread overcrowding was one factor behind a recent wave of violence in Latin American prisons.
"These events reflect an alarming pattern of prison violence in the region, which is a direct consequence of -- or aggravated by -- a range of endemic problems including chronic prison overcrowding, the lack of access to basic services such as adequate floor space, potable water, food, health care and lack of basic sanitary and hygienic standards," Rupert Colville, a spokesman for the high commissioner for human rights, said in a statement.
In Mexico, prison expert Jose Luis Musi said conditions remain ripe for more violence.
"There are many factors," he said. "There is overpopulation, there is complicity and there is a lack of security."
CNN's Rey Rodriguez in Mexico City, journalist Victor Badillo in Monterrey and CNNMexico.com contributed to this report.