MEXICO CITY — Mexican investigators have uncovered 13 more bodies in mass graves in the violent northeastern state of Tamaulipas, where 59 dead were exhumed earlier this week, officials said Friday.
Seventy-two bodies have now been discovered since authorities began chasing reports that gunmen had kidnapped people off of passenger buses running to towns near the U.S. border.Story: Mexican cartels corrupting more US border officials?
Nine of the bodies were discovered in one newly found grave and four in another on Thursday in the area around the city of San Fernando, state Interior Secretary Morelos Canseco said Friday. The total now matches the number of migrants who died in a massacre near that town last August.
Canseco said investigators are searching for more graves in the area.
Federal authorities said Thursday they have detained 14 people in connection with the crimes.
State authorities said they started receiving reports in late March that gunmen were pulling men off buses on the stretch of road that runs through the municipality of San Fernando.Video: Mexican drug corruption crosses the border (on this page)
Relatives of people who have gone missing have begun showing up at a morgue in border city of Matamoros across from Brownsville, Texas, looking for loved ones — some not seen for a couple of weeks, others a few months, some as long as three years.
Authorities are still not sure about the origin of the victims found in the pits, but suspect at least some had been abducted from buses.
Friday's discovery comes just days after thousands of Mexicans protested the country's raging drug war. Also on Wednesday, the day of the march, dozens of bodies were found in graves near the country's border with the United States.
Demonstrators marched in cities across Mexico, holding signs condemning the wave of killing that has claimed more than 37,000 lives since President Felipe Calderon took office in December 2006 and launched a military-led crackdown against drug cartels.
Body counts published by Mexican media indicate the death toll has fallen for two consecutive quarters for the first time since Calderon began his campaign.Slideshow: Narco culture permeates Mexico, leaks across border (on this page)
The tallies point to about 3,220 murders in the first three months of 2011, down from 3,690 in the last quarter of 2010. The government has yet to publish an official estimate.
Although recent estimates suggest the violence may have peaked last summer, Mexicans are jarred by daily news stories of beheadings and executions as cartels war for control of cocaine smuggling routes. Most cocaine consumed in the United States goes through Mexico.Story: 2 Americans killed at Tijuana border crossing
Prosecutors said Wednesday they discovered 59 bodies in a series of graves in the northern state of Tamaulipas, not far from a ranch where 72 Central and South Americans were executed late last year by drug gangs preying on migrants traveling north through Mexico.
Authorities said one grave held 43 bodies, with the rest of the bodies spread among seven other graves.
Investigators believe the recently discovered victims may have been abducted from a bus on March 25, the state prosecutor's office said in a statement.
The Associated Press and Reuters contributed to this report.