Rescuers believe the children – who in addition to the 11-month-old include a 13, nine and four-year-old – have been wandering through the jungle in the southern Caqueta department since the crash.

“At this time there is no other priority other than progressing with the search until finding them,” added Petro. “The children’s lives are the most important thing.”

Petro’s stunning announcement on Wednesday had been met with uncertainty as he gave no details about where or how the children had been rescued, nor how they had survived alone in the jungle.

“Joy for the country,” he had declared.

Amid widespread confusion, the military has not commented since Petro’s announcement on Wednesday.

The children’s grandmother, Fidencio Valencia said there was hope that they would be found alive since “they are used to being in the jungle”.

She said they might be hiding out of fear but she told the Caracol Noticias television newscast that “Indigenous energy” would help the rescuers locate them.

The government’s Institute of Family Welfare said that it had on Wednesday received “information from the territory confirming contact with the four children”.

The plane wreckage. Photo: Colombian Army via AFP

The plane wreckage. Photo: Colombian Army via AFP

It said the report indicated that “they had been found alive and are also in good health”.

However, the agency acknowledged that the military had not been able to “establish official contact” due to bad weather and difficult terrain, and were continuing search and rescue operations.

Avianline Charters, owner of the crashed aircraft, had previously said that one of its pilots in the search area was told the children had been found and that they were being taken by boat downriver.

But the company also said that there was no confirmation that the children were out of danger, and thunderstorms posed a risk to them reaching safety.

On Wednesday, the armed forces had said their search efforts intensified after rescuers came across a “shelter built in an improvised way with sticks and branches,” leading them to believe there were survivors.

In photographs released by the military, scissors, shoes, and hair ties could be seen among branches on the jungle floor.

A feeding bottle found in the jungle. Photo: Colombian army via AFP