Youth members at spiritual retreat for Chains of the Holy Trinity victims of prolonged attack in Mexico City suburbs

An armed gang stormed into a church youth camp near Mexico City and went on an rampage of beatings, robberies and rape, officials said.

Seven girls were raped and several campers were beaten, according to the state prosecutor's office in Mexico state. It said the attack by about a dozen people on Friday lasted for hours and the attackers stole two vehicles as they left.

About 90 youths sponsored by a church group known as the Chains of the Holy Trinity were camping at a spiritual retreat in a park on the eastern outskirts of Mexico City. The park is supposed to be patrolled by police, but the attack occurred late at night and it was unclear whether officers were on duty. Police only found out about the attack when an adult organiser of the camp reported it.

The state government said it had witness descriptions of the attackers and pledged to catch and punish those responsible.

Drug gangs operate on the outskirts of Mexico City, and campers and hikers have also been targeted in the past by common criminals.

Mexico's most populous state was ruled by the president-elect, Enrique Peña Nieto, between 2005-2011. Human rights groups complain that the state has one of the worst records in the country on violence against women. On Wednesday Amnesty International singled out the state for abuses against women and said Mexican police solved one in every 21 rape cases.