An armed gang raped seven young women in a brutal attack on a youth camp just outside Mexico City, state prosecutors said on Saturday, Reuters reports.

Over several hours on Friday, the gang of about a dozen people beat, abused and robbed youngsters at the retreat located in a park in the State of Mexico just southeast of the capital, the local attorney general's office said in a statement.

About 90 youths were camped out there and local media said the victims belonged to a church group.

Mexican daily Reforma said the gang raped seven young women before leaving in two stolen vehicles. The attorney general's office in the state said it had witness descriptions of the attackers.

Mexico's most populous state, the State of Mexico was ruled by President-elect Enrique Pena Nieto between 2005-2011. Human rights groups complain the state has one of the worst records in the country on violence against women.

In a report published on Wednesday, Amnesty International singled out the state for abuses against women, and said Mexican police solve only one in every 21 rapes.