According to rights organisation Save the Children, at least 43 children have been killed by armed forces in Myanmar since February's military coup,
The group said the South East Asian country was in a "nightmare situation", with the youngest known victim just seven years old, reports the BBC.
A local monitoring group puts the overall death toll at 536.
The UN's envoy to Myanmar has warned of the risk of an "imminent bloodbath" as the crackdown intensifies.
The warning follows a flare-up in fighting between the army and ethnic minority militia in border areas.
The unrest in Myanmar began two months ago, when the military seized control of the country after an election which Aung San Suu Kyi's National League for Democracy (NLD) party won by a landslide.
When tens of thousands of people took to the streets nationwide to protest the coup, the military used water cannon to attempt to disperse them. After a week, the response escalated and rubber bullets and live ammunition were used.
The deadliest day of the conflict so far came on Saturday, when more than 100 people were killed.Witnesses say the armed forces have attacked people at random on the streets, and some people have even been killed in their own homes.