By Alberto Fajardo and Ignacio Alvarado

CIUDAD JUAREZ, Mexico, March 28 (Reuters) - Hundreds of camouflage-clad Mexican troops flew into the northern city of Ciudad Juarez on Friday to quell a surge in drug gang murders across the border from El Paso, Texas.

Part of a 2,500-strong army and federal police force set to descend on the dilapidated city over the next three days, the heavily armed soldiers streamed out of military planes and were trucked off to set up road blocks and launch foot patrols.

The troop convoys are opening up a new front in President Felipe Calderon's 15-month-old war on drug cartels. Already about 25,000 soldiers and federal police have deployed in hotspots across Mexico, especially along the U.S. border.

Ciudad Juarez, which has drawn worldwide attention because of a rash of brutal murders of women, has seen 200 people slain in drug-related violence so far this year -- ten times as many as a year ago.

The overall death toll associated with drug gangs in Mexico has rise to more than 720 so far this year, well above the count this time last year.

Mexico's drug wars killed more than 2,500 people in 2007.

The troops in Ciudad Juarez will raid houses, seize weapons and narcotics and purge local police forces accused of working with drug gangs, officials said. Military commanders will take over the day-to-day running of security.

"It's well overdue, but it's a good thing the army has arrived. They are the only ones who can fight the drug gangs, the police are too scared," said Marcelo Acosta, an engineer who last week witnessed a shootout at a busy intersection.

The United Nations and Amnesty International have expressed concern about whether Mexico's use of soldiers against drug gangs risks human rights abuses, following a handful of civilian deaths last year.

Until recently Ciudad Juarez has had a light military presence and analysts say drug cartels have taken advantage of that to try to control smuggling routes to the United States.

Police say Mexico's most wanted man, Joaquin "El Chapo" Guzman, who leads the Sinaloa cartel of Pacific coast traffickers, has taken his fight for control of smuggling routes to the city, targeting the once-mighty Juarez cartel.

The local cartel was weakened by the 1997 death of its leader and is also being attacked by eastern Mexico's Gulf cartel.

Soldiers in Ciudad Juarez seized cocaine, marijuana and heroin bound for the United States and arrested 42 people this week suspected of links to drug gangs, army commanders said. (Writing by Robin Emmott; Editing by Catherine Bremer)

AlertNet news is provided by