The alert came as police on Monday afternoon found the body of a six-year-old boy in the Murray River. He had been missing from nearby Koondrook since Saturday.

The young boy disappeared while swimming in the river at a campsite on Gunbower Island Reserve, near the border town of Koondrook. It is believed his body, found about 7.5 kilometres north from the campsite at Gunbower Island, has been formally identified.

Chief Inspector Michael Tranby said the boy had been swimming with six other children, from two families both from Bendigo, when they started to drift downstream.

Four of the children managed to swim to the river bank, but three others struggled against the strong currents.‘‘Adults entered the water and were able to rescue two of them, but a six-year-old boy went under the water and he did not resurface,’’ Chief Inspector Tranby said.On Sunday, a  four-year-old girl drowned in a creek at Torquay on Victoria’s south coast on Sunday.

Life Saving Victoria operations manager Greg Scott said there had been a significant increase in inland drownings in the past year, as he warned adults to be aware of water conditions and their own abilities before taking a swim.

‘‘Children also need to be closely supervised both in and around water,’’ Mr Scott said. ‘‘Children under five should always be within arm’s reach and children under 10 should always be in your sight.’’

The parents of the four-year-old girl who drowned at the Spring Creek inlet off the surf beach at Torquay said they had taken their eyes off the child for no more than five minutes while they packed up their car on Sunday evening.

‘‘It was just a terrible, terrible incident to happen and to happen right in front of where the parents were,’’ said Noel Dubberley, president of the Torquay Surf Lifesaving Club. ‘‘[It] just goes to point out that you just cannot take your eyes off children anywhere near the water, it just cannot be done.

‘‘As parents we cannot be protective enough around children, you just cannot take for granted their safety around water.

’’The drownings of the two children came after a man in his 40s died on Boxing Day when he reportedly slipped and hit his head on a river houseboat at Mildura.

Another man drowned while swimming at an unpatrolled beach at Venus Bay on Victoria’s Bass Coast, only several kilometres from a patrolled beach on December 21.

And a 25-year-old Iranian man drowned in the Murrumbidgee River at Wagga Wagga, 120 kilometres  north of the Victoria-NSW  border, on Christmas Day. His body was recovered on Monday.

A 10-year review by the Royal Life Saving Society Australia released  this month said the seemingly calm waters of rivers, lakes, creeks and dams often gave swimmers a false sense of security.

‘‘Currents, even in seemingly tranquil waterways, can prove dangerous,’’ the report said. ‘‘Swimmers can also get panicked if they get caught on submerged objects, which are present in many of these waterways,’’ it said.

The Murray River at Mildura is the only inland waterway in Victoria patrolled by lifesavers.But the Royal Life Saving review found the Murray was Australia’s worst river for drownings. Between 2002 and 2012, 43 people drowned along its length.Mr Scott said 47 people drowned in Victorian waterways in 2013-14 – the highest number in a decade.

The majority occurred at unpatrolled waterways. Alcohol was found to be a significant contributor to inland drownings.

‘‘Ensure you understand the conditions and potential hazards before entering the water, by reading the safety signs, or checking with someone familiar with the conditions, such as a local lifeguard or park ranger,’’ Mr Scott said.

‘‘The best way to ensure you go home safely at the end of the day is to swim at one of our 66 patrolled beaches around the state, where our lifesavers can look out for you in the water and assist if you do find yourself in difficulty.’’