CNN  — 

Colombian armed forces have spent more than two weeks searching for survivors of a plane crash in the Amazon jungle, even broadcasting a message recorded by the grandmother of four children onboard, telling them to stay in place.

There appeared to be a breakthrough on Wednesday, when Colombia’s President Gustavo Petro tweeted that the four children – aged 13, nine, four and 11-months old – were found alive. But he later deleted the tweet, saying Thursday that information given to him by the country’s child welfare agency had not been confirmed.

What would be an extraordinary survival story has now confused the nation, with government officials battling poor communications and yet to make direct contact with the children.

The director of Colombian Institute of Family Welfare (ICBF), Astrid Caceres, said her team received second-hand confirmation that search teams rescued and identified the children, who have been missing since the crash of a small airplane in southern Colombia on May 1.

She added that she was “very confident” four children have been found alive more than two weeks after their plane crashed in the Amazon jungle – but was awaiting further proof.

According to the ICBF, the Colombian Armed Forces followed a trail of small objects such as hair scrunchies, plastic wrappings and baby bottles in their search for the missing group.

When asked why the police and military were continuing search efforts despite reports that the children had been rescued, Caceres said: “It’s hard to communicate in the jungle and yesterday it was raining, too.”

“The information I have is that they are fine, we also understand they had very hard days, but these are kids who moved around the area, and they seemed ok,” she added.

“We are still missing that very, very last link that confirms all our hopes. Until we have the photo of the kids we won’t be stopping. We are not underestimating the information we received but we want to confirm [directly] ourselves.”

The Colombian Civil Aviation Authority said in a statement earlier that they found a “shelter built in an improvised way with sticks and leaves.”

Rescuers have been searching for the remnants of the Cessna plane since it crashed on May 1 in the country’s southern region of Guaviare in the Amazonas province.

On Thursday, Colombia’s General Director of the Civil Aviation Authority, Jairo Pineda said three bodies had been recovered and taken to San Jose del Guaviare.

“What we have at this moment is the arrival of three confirmed adult bodies that we are looking at after carrying out a difficult evacuation; they had to be raised by helicopters,” he told reporters in San José del Guaviare.

According to Pineda, two of the deceased are from an indigenous community, and the third body belongs to a pilot.

Authorities said they pursued a trail of small objects such as hair scrunchies, plastic wrappings and baby bottles in their search for the children.

The Colombian Armed Forces’ massive search operation has been supported by dog units, local indigenous communities, planes and helicopters, which flew over the region broadcasting a message recorded by the childrens’ grandmother.

The search intensified on Thursday, evening, according to the Civil Aviation Authority, following the discovery of “new findings that could give clues to (the childrens’) whereabouts.”

“In the last few hours, thanks to the orientation of the canine Ulises, the Special Forces located what would be a makeshift shelter with sticks and branches. There the officers found some scissors and some “monitas” that women usually use to hold their hair.

Hopes of finding the four children alive “remain intact,” it said.

The plane crashed over two weeks ago in Colombia's southern region of Guaviare, in the Amazon jungle.

No photos or videos have yet emerged showing the children.

In his tweet on Thursday, President Petro apologized for saying that the children had been found before confirmation was complete.

“I’m sorry about what happened. The Military Forces and the indigenous communities will continue their tireless search to give the country the news it is waiting for. At this moment, there is no other priority other than moving forward with the search until you find them. Children’s lives are the most important thing.”

CNN’s Claudia Rebaza and Lynn Franco contributed reporting.