Mexico is sending up to 5,000 new troops and federal police to the country's most violent city, where law and order is on the brink of collapse in a war between gangs supplying drugs to the United States.

The army said on Thursday the deployment could take the number of soldiers and federal police to over 7,000 in Ciudad Juarez, which is across the U.S. border from El Paso, Texas.

This month alone, drug hitmen killed 250 people in Juarez, where a meeting of cabinet members on Wednesday was rattled by three bomb scares, forcing soldiers to briefly shut the city's international airport.

"In yesterday's meeting (government officials) talked about sending 5,000 troops and police to Ciudad Juarez," said army spokesman Enrique Torres. "They are expected to arrive in the next few weeks."

At the heavily guarded meeting on Wednesday, Interior Minister Fernando Gomez Mont had said the troop reinforcements would be "notable" but declined to give more details.

Torres said there were 2,020 troops and 425 federal police in Ciudad Juarez, a city of around 1.6 million people.

Drug trade analysts say Mexico's most-wanted fugitive, Joaquin "Shorty" Guzman, who leads a cartel from the Pacific state of Sinaloa, wants control of Ciudad Juarez, currently in the hands of local drug lord Vicente Carrillo Fuentes.

Law and order in Ciudad Juarez is close to collapse as Guzman's hitmen seek to destroy the Juarez cartel's entire operation, drug experts say, and kidnappings and extortions of business people are rampant.

In a what could be a new scare tactic by the gangs, a local newspaper received another anonymous bomb threat on Thursday.

Police evacuated El Heraldo newspaper in the state capital Chihuahua, south of Ciudad Juarez, after a man called the paper to warn of two bombs planted in the building.

It turned out to be a false threat. "It may have been another attempt by organized crime to spread fear or to distract the police," El Heraldo's news editor David Pinon told Reuters.

President Felipe Calderon has sent out some 45,000 troops across Mexico to try and crush drug gangs but clashes between rival cartels and security forces killed around 6,000 people last year.

The United States supports Calderon's military operation and is concerned the violence could destabilize Mexico, a key trading partner, and spill over the border.

A U.S. Senate committee said on Thursday it would discuss hold two meetings on the surging violence along the border, days after the Obama administration warned travelers about the growing risks there.

"The recent escalation of violence along the southern border demands our immediate attention," said Senator Joseph Lieberman, chairman of the Homeland Security and Governmental Affairs Committee.

"We must assess border security programs and plans in place and we must review the readiness of federal, state, and local law enforcement," he said. The panel would examine how the two governments were addressing the situation and determine the potential for increased terrorist activity.

The committee said it may also look into whether there is merit to deploying National Guard to the border, fencing issues and potential mass migration from Mexico.