TEPECOACUILCO, Mexico (Reuters) - Beside a one-lane highway in southwestern Mexico, surrounded by green fields and wildflowers, investigators combed a dump on Friday for any trace of 43 student teachers whose disappearance has haunted the country for five years.

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Donning gloves and surgical masks, half a dozen people stood by as an earthmover extracted heaps of dirt, with colorful pieces of trash gleaming in the sun, part of President Andres Manuel Lopez Obrador’s pledge to reveal what happened to the students.

A few dozen armed soldiers were on guard scattered around the site, which was largely overgrown with trees and shrubs. A ribbon of yellow caution tape stamped with the words “Criminal Prosecution” and a barbed wire fence prevented onlookers from drawing any closer than the entry gate.

The dump is one of the latest fronts in a search that has produced more questions than answers since the students vanished on the night of Sept. 26, 2014, sparking international outrage and doing lasting damage to the administration of Mexico’s then-president, Enrique Pena Nieto.

The government has given no details so far on what has been found at the site, but after pacing muddy dirt trails wearing a surgical mask, Mexico’s deputy interior minister, Alejandro Encinas, on Friday afternoon hinted that it would prove significant.

“We’ve now realized this is an important site, a very important site,” Encinas, the official in charge of human rights, said as he got into his car, without elaborating.

The Mexican public has grown accustomed to false starts and dead ends. Indeed, authorities said last week that the investigation had been so plagued with errors that they would be virtually starting from scratch.

Located in Tepecoacuilco, a few miles from the southwestern city of Iguala where the students were abducted, the dump is one of dozens of sites within five municipalities that officials have searched in recent weeks, Encinas said on Thursday, wearing a T-shirt stamped with the number “43” in remembrance of the students.

In a grim reminder of the prevalence of unmarked graves in the violent southwestern state of Guerrero, authorities have found 184 bodies so far, Encinas said, but none belonged to the missing students.

According to the Pena Nieto administration, local drug gang Guerreros Unidos mistook the students for members of a rival outfit, killed them, incinerated their bodies in another nearby dump and tipped their remains into a river.

However, the remains of only one of the 43 were ever definitively identified. A group of independent experts later picked several holes in the official version of events presented in 2015.

In the nearby town of Huitzuco, site of another probe that Encinas said is ongoing, Marco Moyo said he was heartened to see investigators taking new tacks in the search.

“It’s interesting to see them looking in different places where they hadn’t looked before,” said Moyo, a 30-year-old student. “They could probably find different clues.”

Nevertheless, he said he feels that the sense of anger around the students’ disappearance is fading with each passing year. And such disappearances have some become so commonplace in Mexico that many other cases are all but an afterthought.

“There are too many of them,” Moyo said. “Authorities don’t devote time to investigating them, and there isn’t interest in investigating either.”