Soldiers dug through tons of mud and dirt in search of victims of a massive landslide, as Mexican authorities looked for a police helicopter that went missing while carrying out relief operations on the flood-stricken Pacific coast.

Barack Obama has discussed the National Security Agency’s surveillance programmes with the presidents of Mexico and Brazil, the White House said.

Rescue teams worked through the night to pull out survivors after a massive explosion at the main headquarters of Mexico’s state-owned oil company killed 14 people and injured 100.

MEXICO’S new president has vowed to demilitarise the campaign against drug cartels, but thousands of troops likely will remain in the field for years to come, spearheaded by US-favoured naval infantry.

Mexico’s president-elect said the private sector must be allowed to help modernise his country’s state-owned oil company to increase productivity and make it more competitive.

Thousands marched through Mexico City, railing against what they called the “imposition” of the old ruling party candidate as the country’s new president.

Mexican authorities are recounting more than half the ballot boxes used in the presidential election after finding inconsistencies in the vote tallies.

Mexico’s old rulers have claimed victory in a presidential election, ending 12 years in opposition after a campaign dominated by a sputtering economy and rampant drug violence.

Mexico’s old guard sailed back into power after a 12-year hiatus as the official preliminary vote count handed a victory to Enrique Pena Nieto, whose party was long accused of ruling the country through corruption and patronage.