MEXICO CITY _ Allegations of election fraud swirled as voters in four Mexican states went to the polls Sunday, and the country's long-dominant political party endeavored to avert a devastating loss before next year's presidential election.
Officials and the media reported hundreds of irregularities, including bloody pigs' heads found outside opposition offices, telephone threats to discourage voters, alleged vote-buying and the organized busing of unregistered voters to the polls.
Authorities vowed to investigate the charges, but as the polls began to close late Sunday, it was unclear whether the allegations of improprieties would trigger appeals. Official results were expected late Sunday and on Monday.
Turnout was said to be moderate under sunny skies in the most critical balloting venue, sprawling Mexico state, home to more than 11 million voters, the most in the country.
The ruling Institutional Revolutionary Party, known as the PRI, has never lost the governor's seat in Mexico state, a jumble of 125 cities and towns outside the national capital.
The election there is widely viewed as a test of the PRI's ability to retain the presidency in national voting scheduled for July 2018.
President Enrique Pena Nieto, the PRI standard-bearer and a former governor of Mexico state, is saddled with low approval ratings amid rampant crime, rife corruption and a sluggish economy.
Polls have showed a tight race in Mexico state between two leading candidates: The PRI's Alfredo Del Mazo Maza, 41, the son and grandson of former state governors and a distant cousin of the president; and Delfina Gomez, 54, a former schoolteacher running under the banner of the left-wing National Regeneration Movement, known as Morena.
The PRI held the presidency for most of the 20th century before suffering successive losses in 2000 and 2006. Pena Nieto regained the top office for the PRI in 2012, but his lack of popularity could cost the party next year.
Seeking to head off a humiliating defeat in Mexico state, the PRI mobilized its daunting electoral machine to boost turnout in its stronghold.
As polls closed Sunday, both the PRI and Morena publicly declared that exit surveys had showed their candidates headed toward victory.
The national head of Morena, Andres Manuel Lopez Obrador, is looking for a Morena victory in Mexico state to jump-start his third run for the presidency. Lopez Obrador, who said he was twice cheated out of presidential triumphs, has accused other parties of engaging in a "dirty war" there.
The PRI was also trying to maintain its gubernatorial seats in the northern border state of Coahuila, along the Rio Grande with Texas, and in the Pacific coast state of Nayarit.
In addition, voters in the Gulf of Mexico state of Veracruz were electing mayors in 212 municipalities. The PRI lost the governors' posts last year in Veracruz and neighboring Tamaulipas state, both of which had long been ruling-party bastions.
