MEXICO CITY - A group of unknown gunmen kidnapped nine police officers in the southern Mexican state of Guerrero, authorities said on Saturday.

Unconfirmed reports said the bodies of two officers were found later in a northern part of the state.

Fernando Monreal Leyva, director of the State Investigative Police, was quoted as saying that contact with the police officers, who were investigating a murder case in the state, was lost Saturday afternoon.

Army troops were were helping search for the missing.

Meanwhile, authorities in Ciudad Juarez, Mexico's most violent city in the northern state of Chihuahua, said police had detained two alleged gang leaders linked to at least 10 murders, including the killing of a federal police officer last month.

One of the detainees was identified as Gonzalo Dominguez Sanchez, known as "El Chore," who, according to the federal police, was the successor to alleged Aztecs leader Jesus Ernesto Chavez Castillo.

Police said the men were caught with an AR-15 rifle, two loaded pistols and over 1.6 kg of cocaine.

Ciudad Juarez had the world's highest murder rate in 2009, despite the government's reinforcement of army and police to the city, where mobsters were widely seen as having overpowered municipal and state authorities.

The war on smugglers, whose main business is transporting drugs into the US, has been a key plank of the presidency of Felipe Calderon, who took office in December 2006.

According to government figures, 28,000 people have died in the anti-smuggling campaign since 2006, most of them gangsters murdered by rivals.