Local Weather Forecast
Today: Current:54	Sunday: 86/62	Monday: 90/70
Complete Forecast for  May 17 2008

MEXICO CITY (AP) -- Federal agents arrested four police officers just south of the border with Texas on Saturday and were investigating where they got their guns, Mexican police said.

In a joint operation, federal police and soldiers arrested the officers early Saturday morning in the city of Nuevo Laredo across the border from Laredo, Texas, said a spokesman for Mexico's Public Safety Department who requested anonymity because he was not authorized to speak on the matter.

"The army has stepped in to investigate the origin of their weapons," he said.

Mexican radio station Formato 21 said the officers had guns that weren't registered with their unit in the border state of Tamaulipas.

It wasn't immediately clear if the four officers were being investigated for corruption, which is widespread in Mexico, particularly in states like Tamaulipas plagued by organized crime.

In October, 25 federal police officers were detained in the state on suspicion of providing protection for the powerful Gulf drug cartel.

Mexico has long complained that much of the violence is fueled by U.S. guns smuggled south of the border, where drug traffickers and other organized gangs sometimes outgun police.

On Wednesday, U.S. Attorney General Michael Mukasey said the U.S had begun giving Mexico access to an electronic database that lets police determine the origin of weapons seized from criminals and then notify U.S. authorities, who can then crack down on gun dealers.

The arrests Saturday came after two weeks of bloody clashes along the border between federal agents and gunmen allegedly working for the Arellano Felix and Gulf cartels.

On Thursday, a federal agent and a gunman who allegedly worked for the Arellano Felix cartel where killed in a three-hour shootout in Tijuana that forced the evacuations of nearby schools. Earlier in the week, gunmen shot dead three police officials and one of their wives in the city.

On Jan. 10, gunmen shot and killed two federal agents and a civilian in the central state of Michoacan. Two days earlier, two other federal agents were killed and three were injured during a shootout in Reynosa, across the border from McAllen, Texas.

A day before the Reynosa shootout, three suspected criminals were killed and 10 federal agents and soldiers wounded in a shootout in the town of Rio Bravo, across the border from Donna, Texas.