Akon Guode, centre leaning on a friend, has admitted murdering her children (Photo: Getty)

A mum has pleaded guilty to murdering three of her children by driving her car into a lake.

Twins Madit and Anger Manyang, four, and Bol, one, all perished when their mum's four-wheel-drive car became submerged in a lake in Melbourne, Australia.

Now Akon Guode, 37, had admitted murdering the three siblings and attempting to murder their older sister Awel, six, who was left fighting for her life after the crash.

Police accused Guode of driving into Lake Gladman on purpose, but she initially claimed she was not responsible because she was under the "spell" of witchcraft at the time.

Victoria Police collision investigator and civil engineer Detective Senior Constable Robert Hay said: "From the drive-throughs of the collision scene, it is my opinion that the car could not and did not just drift off the roadway."

The grey 2005 Toyota Kluger smashed through shrubs as it careered towards Lake Gladman before continuing for another 10 metres and sinking.

From left, Bol, Anger and Madit all died in the crash

The heartbroken father of the children, who came from a Sudanese family, initially believed the crash was an accident.

Describing the children's mother, he said: “She is a very good mother. She was very happy. I don’t think she planned to do anything.”

Frantic police and passers-by immediately leaped into action and dived into the water to try and help all those in the car.

Rescuers began smashing windows in a desperate effort to pull children free of the partially submerged car.

Seventeen-year-old Sara Omar was walking in the parklands near the lake’s edge as the people-carrier ploughed into the lake and saw a man race to help.

She said: “I didn’t really see much because I was around the other side, but I heard a massive ‘boom'. He broke the window of the back seat of the car and he tried to take the little kids out and he put them on the end of the lake. I saw the ambulance taking a little kid and I think they were resuscitating him.”

Another resident said a neighbour known as Travis was among those who helped the tragic children.

She said: "It’s just a horrible scene. Travis jumped into the water, smashed the back screen of the car and got one little boy out. Then they started working on him.”