The federal government has released 57 million pesos ($4.8 million) in security assistance for Ciudad Juarez, Mexico's murder capital, the Chihuahua state government said.

The funds were frozen late last month because federal officials claimed Ciudad Juarez had failed to improve the quality of its police force.

The funds were restored thanks to the efforts of Chihuahua Gov. Cesar Horacio Duarte, who spoke with Government Secretary Francisco Blake, state officials said.

Ciudad Juarez also verified that it complied with the requirements of the security assistance fund, known as the Subsemun, state officials said.

The subsidy from a fund to improve municipal public safety nationwide was frozen on July 28, the National Public Safety System Executive Secretariat, or Sesnsp, said in a statement released last week.

The Subsemun is one of three funds set up by the federal government in an effort to professionalize state and local police forces and equip them with the resources to take on heavily armed, well-funded drug cartels.

Juarez authorities failed to meet a series of requirements for receiving the subsidy, including evening out officers' salaries and adopting a personnel management system aimed at boosting professionalism, the Sesnsp said.

The government appropriated a total of 95 million pesos ($8.1 million) from the Subsemun for Ciudad Juarez in 2010, of which 38 million pesos ($3.2 million) was delivered earlier in the year.

From 2008 to 2010, Juarez, a city of 1.2 million people, only trained 145 police officers with Subsemun funds, equivalent to "just a 6 percent advance in the professionalization of (the municipal police personnel)," the Sesnsp said.

Over the same period, not a single command-level officer was trained in the border city, whose homicide rate is among the highest in the world, the Sesnsp said.

The federal government has deployed 5,000 Federal Police officers in Ciudad Juarez and several thousand army troops at strategic locations around the city, such as the airport, on a permanent basis.

Numerous shootouts between federal and local officers have occurred, prompting complaints from Juarez officials.

Juarez police chief Julian Leyzaola said last week that at least 20 Federal Police officers shot at vehicles carrying him and his bodyguards in the wee hours on July 26 as he was traveling to the municipal jail to quell a riot that left 17 inmates dead.

The Federal Police said Leyzaola failed to stop at a checkpoint or identify himself.

City clerk Hector Arcelus, however, dismissed the federal cops' claim that the shooting was the result of confusion.

The federal officers are "perfectly" familiar with the vehicles used by Leyzaola and his security team, according to Arcelus, who said it was "neither logical nor credible that they (the federal officers) acted randomly."

The Federal Police killed a member of Mayor Hector Murguia's security detail at a checkpoint in Juarez in January.

The mayor, who demanded that the officer who shot his bodyguard be charged with homicide, subsequently got into a shouting match with the federal cops, who pointed their assault rifles at Murguia during a chance encounter in the city.

At least 14,000 "armed criminals" are in Ciudad Juarez and Chihuahua city, the state capital, working for the drug cartels that are fighting for control of smuggling routes into the United States, Chihuahua Attorney General Carlos Manuel Salas said earlier this year.

About 5,500 of the armed criminals operating in Ciudad Juarez belong to Los Aztecas, a gang that works as the armed wing of the Juarez cartel, while the rest work for the Sinaloa cartel, Salas said.

More than 3,100 people were murdered in the border city last year, making 2010 the worst year since a war between rival drug gangs sent the homicide rate skyrocketing in 2008.

The murder rate remains high this year, with more than 1,000 people slain thus far in Juarez, but is down from 2010.