Only a fraction of the abuses the Iran-backed Houthi rebels have committed against children in Yemen have been documented since the war began in 2014, the country's Minister of Legal Affairs and Human Rights said.
"The Houthi militia have been covering up the real number of recruited children who were killed while fighting in their ranks," Ahmed Arman told The National on Saturday.
"[Houthi rebels] have deceived the international community through medical facilities in areas under their control where they register children who were killed while fighting with them as victims of coalition air strikes."
He demanded a transparent investigation into offences against civilians so those responsible could be held to account.
It comes after Liz Throssell, spokeswoman for UN High Commissioner for Human Rights, on Friday called for an investigation into attacks that led to civilian deaths and significant damage to national infrastructure.
"We are seriously concerned at the continuing impact of fighting on civilians and the targeting of civilian objects in Marib governorate in Yemen, which Houthi forces, also known as Ansar Allah, have been trying to seize from the Yemeni government for several months," Ms Throssell said.
Houthi rebels in Yemen have recently increased attacks near residential areas, causing dozens of civilian casualties.
At least eight people were killed in a combined drone and missile strike in the northern city of Marib last week.
On June 5, at least 17 civilians were killed in an explosion near a petrol station in Marib province.
Yemeni officials blamed it on a Houthi missile after the group claimed to have struck a military target.
“We call on all parties to the conflict to respect their obligations under international humanitarian law, including their obligation to respect the principles of distinction, which prohibits the targeting of civilians and civilian objects and infrastructure, as well as the principles of proportionality and precautions in attack,” Ms Throssell said.
“All parties to the conflict should ensure that any attacks resulting in the death of civilians and destruction of civilian infrastructure are meaningfully investigated.
"Victims of arbitrary killings, including those amounting to war crimes, have a right to justice, and perpetrators of such acts, regardless of affiliation, must be duly held to account."
Houthi rebels in Yemen have continued their cross-border attacks into Saudi Arabia.
On Saturday, the Saudi-led coalition said its air defence system intercepted seven booby-trapped drones launched by the Iran-backed rebels towards the south of the kingdom.