Scores of children have been killed in Myanmar since last year’s coup, not only in the crossfire of conflict but as deliberate targets of a military willing to inflict immense suffering, a UN expert said on Tuesday.

Minors had been beaten and stabbed and had fingernails or teeth removed during interrogation, and some were made to endure mock executions, according to a report from UN special rapporteur on human rights in Myanmar, Tom Andrews.

The junta has repeatedly scolded the UN and Western countries for interference and rejected allegations it is carrying out atrocities. A military spokesperson could not be reached for comment on Tuesday.

Based on contributions from UN agencies, humanitarian and human rights groups and civil society organisations, the report said 250,000 children were displaced by fighting, and at least 382 killed or maimed, including by air strikes and heavy artillery.

“The junta’s relentless attacks on children underscore the generals’ depravity and willingness to inflict immense suffering on innocent victims in its attempt to subjugate the people,” Andrews said.

“Its attacks on children constitute crimes against humanity and war crimes.”

Myanmar has been in turmoil since the military seized power early last year and launched a fierce crackdown on its opponents, prompting a violent backlash by newly formed resistance groups.

The UN had received information of 142 children being tortured by soldiers, police and pro-army militias, the report by Andrews said, while there were anecdotal reports of an increase in child labour recruitment, including by anti-junta fighters.

Andrews said the world should take co-ordinated action to isolate the junta financially and commit to a “dramatic increase” in humanitarian assistance.

He said UN members “must respond to the crisis in Myanmar with the same urgency they have responded to the crisis in Ukraine”.