Body count in Mexico mass grave jumps to 33

MEXICO CITY, March 14 (Reuters) - The number of bodies dug up in the back yard of a house in the crime-ridden Mexican border city of Ciudad Juarez has leaped to 33, the attorney general's office said on Friday.

Nine bodies were initially found at the makeshift grave when police began digging there in late February, tipped off by an anonymous source following a drug bust at the house. Police believe the bodies are victims of the Juarez drug cartel that operates in the area.

"It is presumed that they were all killed by guns," an official at the attorney general office said on Friday, asking not to be quoted by name. The attorney general's office gave the new body count in a statement late on Thursday and said police would keep searching the area for more bodies.

Ciudad Juarez, across the border from El Paso, Texas, has drawn worldwide attention in recent years due to a series of brutal murders of women that have gone largely unsolved and rising drug killings.

The latest 33 bodies found had been buried for about five years, according to preliminary forensic tests. Only three were women and none of the corpses have been identified.

Mexico's northern states have become a battleground for powerful drug cartels vying for control of the best smuggling routes to the United States.

Ciudad Juarez is a stronghold of the Juarez cartel, which was weakened by the mysterious death in 1997 of its leader Amado Carrillo Fuentes as he was undergoing plastic surgery.

The drug raid at the house where the bodies were found led to two arrests and the seizure of 1.7 tonnes of marijuana.

The Mexican army and federal police have hit drug cartels with a rash of drug seizures and arrests under a nationwide crackdown on smugglers started by President Felipe Calderon when he took office in December 2006.

Mexican drug violence killed more than 2,500 people last year and drug gang-related deaths this year total well over 300. (Reporting by Cyntia Barrera Diaz and Miguel Angel Gutierrez; Editing by Catherine Bremer and Bill Trott)