The first occurred on Saturday in Lefaga where a one-year-old boy is believed to have drowned behind the family home.
The police said the child was left unsupervised.
The second death was that of a four-year-old girl in Ti'avea, who died on Sunday after being hit by a mini-van while she was crossing the road.
The police said the driver has been charged with negligent driving causing death.
Then on Monday, a three-year-old was killed while watching television with her siblings when the television fell on her head.
The police have called on the public to ensure the safety of children, which they say should be every community's first priority.