Two young Aboriginal brothers who went missing from their home have now been found dead in a river, according to authorities.

Just before 7 am on Tuesday, five-year-old Barak and three-year-old Jhulio were found submerged in the Ross River near Cranbrook in Townsville, stated a Daily Mail report.

CCTV footage showed both youngsters for the last time as they walked towards the river, with the elder brother still wearing his school uniform. After the boys went missing from their home in the suburb of Cranbrook at about 5.30 pm on Monday, police issued an amber alert.

The devastated mother Leeann Eatts made several calls on social media to help find her boys before their bodies were discovered in the water body. "Mum is missing you boys so much," Eatts posted to Facebook. "My two babies have been missing since 5.45. I got eight police cars at my house and everyone on foot looking for them please keep a close eye out for them on the streets... they just walked off. Please help Townsville. I am so tired and empty."

The embattled mother thanked those involved in the search for her "two wonderful boys" just moments after their bodies were found. A witness at the scene said they saw the boys swimming in the river, Senior Sergeant Ian Wilkie said. According to him, the deaths were the result of a "tragic accident."

Speaking to Sunrise, Wilkie said, "Where they'd been jumping in swimming, it's quite deep and it's got a steep bank and there are weeds and other debris in that area. They looked like they were having fun and it's turned to tragedy. Our hearts and thoughts go out to the family."

Residents in the region were recently battered by destructive weather and floods, thereby making the tragedy even worse, Wilkie added.

"We all know it has been a challenging month for Townsville as it is and the entire community pitched in to search for these boys," he told The Today Show.

"It is certainly distressing for us and we can only imagine what the families are going through and our heart and thoughts are going to them. The grief I could imagine would be unbearable for them. We hoped for a better outcome. Unfortunately, that wasn't to be... the community came out in force last night. We were hearing stories of dozens of people searching in various areas, going and buying batteries for torches. We do thank them for the assistance in this. Unfortunately, it wasn't to be."

Late Monday night, a member of the public tipped police off saying they had seen the boys jumping into the Ross River.

Over 60 police officers with assistance from fire crews and State Emergency Services volunteers subsequently carried out the search operation before their bodies were found.

While the boys often played at Cranbrook Park, they did not come home at their usual time, Wilkie said. Overnight, as officers rode on motorbikes up and down the Ross River in search of the boys, a police helicopter also joined the pursuit.

"We do believe that the boys, given their age, are quite possibly frightened and that they are small, they are curled up somewhere," Wilkie said, adding that their family was "distraught and upset" after the pair went missing.

Calling the deaths an "absolute tragedy," Townsville MP Scott Stewart told ABC: "My thoughts and prayers go out to the family of these kids — I can't imagine what they are going through, the anguish, the heartbreak."

Stewart then lauded those who turned out in droves to help locate the youngsters. "It's that Townsville strong spirit that we have... we band together, we look after one another, and this is where we stand strong together and this is where we rely on the community to get us through these tough times," he said.