Luis Cardenas, the regional security chief for the federal police, said that the group killed two federal officers in Juarez last week. One of the officers had apparently been hacked to death.

Most killings in Ciudad Juarez are attributed to disputes between the Juarez and Sinaloa gangs over control of lucrative drug trafficking routes into the United States.

Reporters kidnapped

On Thursday, five suspected members from the Sinaloa cartel run by Mexico's most wanted man - Joaquin "Shorty" Guzman - were arrested and presented to the media.

The suspects were arrested in the state of Durango.

"Elements of the federal police arrested five members of a criminal group, at the service of the Sinaloa cartel, who allegedly participated in the kidnapping of reporters last July 26," Cardenas told reporters during a presentation.

The members of the Sinaloa cartel, Mexico's most powerful drug trade organisation, said they abducted the journalists in the northern state of Coahuila to demand their networks broadcast their messages.

Also on Thursday, nine men from the Gulf cartel were presented to the media after being arrested on murder charges.

Meanwhile, Felipe Calderon, the Mexican president, has been holding anti-crime strategy meetings this month over his controversial deployment of tens of thousands of soldiers to take on organised crime gangs.

The security situation however continues to deteriorate and some areas of Mexico along the US border have also been paralysed economically by drug violence.

The governor of the border state of Tamaulipas said on Thursday that the federal government should send relief funds.

Economic impact

Violence has affected tourism, commerce and investment, Eugenio Hernandez said during a meeting between his counterparts and Calderon.

"It is necessary to send additional funds to reactivate the economy in the affected zones," Hernandez said.

At least 28,000 people have died in drug violence during Calderon's term as president [Reuters]

"The climate of lack of safety has reduced the flow of foreign investment, and it is urgent that a promotional campaign be designed to improve the country's image."

Hernandez did not specify which areas were paralysed, but people in Tamaulipas cities such as Nuevo Laredo, Reynosa and Matamoros on the border with Texas say bloody turf battles between drug gangs have caused a decline in business.

Much of the region's employment comes from foreign-owned border assembly plants

Calderon has been meeting with opposition parties, academics and civic groups as part of an unprecedented series of talks about his offensive against drug cartels - which has been criticised as making the country less secure.

He has used the forum to open the door to news ways of combatting organised crime, including stricter measures against money laundering and possibly the first-ever restrictions on cash transactions.

He also said last week that he would consider a debate on legalisation of drugs, though he personally opposes the idea.