18 January 2012 Last updated at 16:47 ET

The Mexican army says it has rescued three children who were being held by a suspected criminal gang.

Officials said the children had been chained and locked up in a private home in the central city of Temixco.

Inside the home, soldiers also found the decapitated body of a man, whose head had been dumped on Tuesday.

Thirteen people suspected of belonging to a criminal gang specialising in theft, kidnapping and drug trafficking were arrested during the raid.

No information was released about the children, or where and when they may have been abducted.

Officials only said they would be receiving psychological counselling.

Growing violence

The army said the body found in the apartment belonged to Eduardo Gonzalez Mora.

His head had been found inside a motorcycle helmet in the nearby town of Nueva Morelos de Xochitpec on Tuesday.

A threatening message had been left next to the head signed by a criminal gang calling itself "Los Rojos" (Red Ones).

Officials said very little was known about Los Rojos.

Morelos state, where Temixco is located, has seen a number of violent events in recent weeks.

On Monday, unidentified gunmen killed the police chief of Zacatepec, also in Morelos.

There have also been a number of shoot-outs over the past months.

Until recently, Morelos had escaped the high levels of violence seen in some other regions of Mexico.

BBC News - Mexican army frees three children held by alleged gang