Their mother and the other adults were killed in the crash.

The government's child welfare agency, ICBF, said it had received information "from the field" that the children had been found in good health.

A pilot said he had also been told the children had been found by indigenous people deep in the rainforest.

Soldiers taking part in the search, however, have yet to see the children for themselves.

The Cessna 206 light aircraft they had been in was flying from Araracuara, deep in the Amazon jungle in southern Colombia, to San José del Guaviare, when it disappeared in the morning of 1 May.

Its pilot had earlier reported engine problems.

After a huge search effort involving more than 100 soldiers, the plane was finally located on Monday, two weeks after it had disappeared.

The bodies of the pilot, the co-pilot and 33-year-old Magdalena Mucutuy, the mother of the four children, were found at the crash site in Caquetá province.

But the children, who are aged 13, nine and four years, as well as an 11-month-old baby, were nowhere to be found.

The search teams have, however, found clues indicating that the children, who are from the Huitoto indigenous group, survived the crash.

Sniffer dogs came across a child's drinking bottle, a pair of scissors, a hair tie and some half-eaten fruit.

The search teams also found an improvised shelter made from sticks and branches.

"We think that the children who were aboard the plane are alive. We have found traces at a different location, away from the crash site, and a place where they may have sheltered," Colonel Juan José López said on Wednesday.

Fearing that the children were wandering ever deeper into the jungle, the military deployed helicopters which played a recorded message from their grandmother in the Huitoto language urging them to stay put.

The search was hampered by heavy rains, but on Wednesday Colombia's Institute for Child Welfare told Colombia's president it had received reports "from the field" that the children had been found by locals.

President Petro tweeted the news, saying the had been located "after an arduous search".

However, confusion arose when Colombia's armed forces said they themselves had not yet been able to make contact with the children "due to the difficult meteorological conditions and the difficult terrain" - and could not confirm the news of their rescue.

Meanwhile, Avianline, a local plane operator which owned the crashed plane, released a statement saying that it too had received reports that the children had been found.

One of its pilots landing on a dirt strip in Cachiporro, a community near the crash site, was told that locals there had been contacted by radio from a remote location called Dumar and been told that the children had been found. They would be taken by boat to Cachiporro, he said.

The company added that it had no way of confirming if the information was correct, but it did point out that the arrival of the children by boat may have been delayed by heavy rains, which have made the river too dangerous to navigate.

Indigenous radio stations have also reported that the children were found by a local, and were being transported by river to Cachiporro.

President Petro has not released any news on the children since the tweet in which he announced that they had been located.

The children's father had earlier said that he was not giving up hope. He told Caracol Radio that his sister had once been lost in the forest for a month and managed to return.

It is thought that the Huitoto people's knowledge of fruits and jungle survival skills will have given the young children a better chance of surviving the ordeal.