Mexico’s federal police agency says it has fired nearly 10 percent of its force this year for failing lie detector and other tests.

Mexico’s approximately 35,000 federal police are required periodically to take lie detector, psychological and drug tests. The government also routinely investigates their finances and personal life.

A Mexican soldier said that a U.S. citizen attacked an army convoy and was killed when troops shot him in self-defense outside the resort city of Acapulco, a police official said. The man’s father said Monday that he found it hard to believe.

An army sergeant told police that Joseph Proctor opened fire on a military convoy with an AR-15 rifle, forcing the soldiers to shoot back, said Domingo Olea, a police investigator in the western state of Guerrero, where Acapulco is located.

The U.S. National Hurricane Center says a low pressure system over the southeastern United States will move towards the Gulf of Mexico, site of the worst oil spill in U.S. history, and has a 30 percent chance of becoming a tropical storm in the next 48 hours.

Forecasters warned Sunday that the system could move over warm water in the Gulf by early Monday.

The U.S. National Hurricane Center says a low pressure system over the southeastern United States will move towards the Gulf of Mexico, site of the worst oil spill in U.S. history, and has a 30 percent chance of becoming a tropical storm in the next 48 hours.

Forecasters warned Sunday that the system could move over warm water in the Gulf by early Monday.

Spain set off Monday on the long trip to face Mexico in what will be their first international since winning the World Cup for the first time.

La Furia Roja set off for Mexico City, where they are scheduled to play in the Azteca stadium as part of their hosts’ bicentenary celebration of independence from Spain.

Celtic have completed the signing of the Mexico international Efraín Juárez, who joins the club on a four-year deal.

The 22-year-old defender, who played for his country at the World Cup in South Africa, becomes the latest recruit to join the Hoops and will be officially unveiled this afternoon at Celtic Park.

U.S. National Guard troops will begin arriving along the border with Mexico on Aug. 1 to bolster security as the Obama administration tries to stem the flow of illegal immigrants, weapons and narcotics, U.S. officials said on Monday.

In addition to the deployment of National Guard troops, some 300 more Customs and Border Protection agents and officers will be sent to the border region, along with additional helicopters and other surveillance equipment, they said.

A shift from military to police control is part of a broadened strategy aimed at curbing violence that has killed more than 5,000 people in Ciudad Juarez since 2008. So far, the results are mixed. The rifle-toting Mexican soldiers who patrolled in convoys have been sent to the barracks.

Tropical Storm Alex weakened to a depression Sunday hours after making landfall in this popular tourist destination, but is expected to regain strength in the coming days as it moves out over warmer waters in the Gulf of Mexico. More >

Mexico and Uruguay know just a point apiece from their meeting on Tuesday will see them into the last 16.

Conspiracy theorists have suggested that the pair will play out a tame stalemate in Rustenburg, ensuring they both progress into the knockout stages.

Both sides have been quick to play down such talk, though, with top spot in Group A still up for grabs.

Finishing in first place could prove crucial, as the runners-up are likely to be paired with free-flowing Argentina in the next round.