Mexico has deployed 1,500 more troops to the northern border city of Ciudad Juarez, where homicides related to the drug trade have surged in recent weeks.

The extra soldiers will begin patrolling the city Monday, said Enrique Torres Valadez, the spokesman for the joint security operation of soldiers and state police in Ciudad Juarez.

A total of 2,500 troops arrived Saturday night in the city across the border from El Paso, Texas, Torres said, though about 1,000 of them are relieving soldiers already on duty there.

Drug-related killings in Ciudad Juarez declined to about one per day after the army sent some 5,000 troops there in March, bringing the number of soldiers patrolling the streets to about 7,000.

As homicides declined, some troops withdrew. But last week, the Chihuahua state attorney general's office said killings in Ciudad Juarez have risen again to an average of eight to nine per day. State officials haven't given a reason for the increase.

Through mid-June, there have been 800 killings in the city of about 1.3 million people, a level similar to the approximately 1,600 deaths in 2008.

With the deployment Saturday, 5,500 troops are now in Ciudad Juarez with another 1,300 patrolling surrounding areas.

Local, state and federal forces will step up patrols in the most dangerous parts of the city and increase checks of suspicious vehicles, Chihuahua state Public Safety Secretary Victor Valencia said last week.

Local police have been working alongside the army, which is scheduled to begin withdrawing later this year. The resurgence of homicides, however, calls into question whether that withdrawal will be possible so quickly.

The federal government is recruiting, equipping and training Ciudad Juarez police with the goal of bringing the force to about 2,500 by September and 3,000 by the end of the year.

But the force, which currently numbers 1,200 officers, has lost people faster than it can replace them. More than 900 agents were fired, resigned or retired last year.

Some were dismissed after failing psychological, background and other checks as part of a campaign to clean up the department. But others quit after watching colleagues gunned down by drug gangs or seeing their names turn up on hit lists left in public.