Yemen's Houthi rebels killed three children this week in the south-western province of Taez.
The rebels have besieged Taez, Yemen's second-largest city, for more than four years.
“Amr Yaqoub, 13 years old, was killed in Asifra district in northern Taze, after being shot in the head,” local media reported.
On Tuesday, two others were killed and six injured after a rocket-propelled grenade targeted a residential village in Masrakh district, in southern Taez.
The Houthi blockade has brought residents to the brink of catastrophe.
Yemenis took to social media to vent their frustration and called on the UN to take a firmer stance against the rebels.
"The UN Envoy to Yemen, Martin Griffiths, must move rhetoric to action and assume a bigger role in holding Houthis accountable in Taez," Fatima Alasrar, a Yemen expert and senior analyst for the Arabia Foundation, said on Twitter.
“Yemenis mourn more deaths today by Houthi snipers in Taez,” she said.
Children in the besieged Houthi-held city have been traumatised by daily artillery fire, rockets and anti-aircraft gun, aid agencies say.
More than 24 million Yemenis, who make up 80 per cent of the population, now need some form of humanitarian aid or protection, and as many as half could face starvation if aid agencies don’t reach them with food and other assistance, according to the Norwegian Refugee Council.
The rebels still control Yemen’s most populated areas including the capital Sanaa and the port city of Hodeidah.
Meanwhile, the start of the Eid holiday this week become politicised this week after Houthi rebels arrested and killed several civilians for ending Ramadan on Tuesday in line with parts of the country controlled by the government.
The Iranian-backed militias declared that the holiday was to start on Wednesday.
The rebels shot dead an imam and nine other civilians following attacks on mosques after civilians refused to stop their Eid prayers in the capital Sanaa.
“The Houthi militia prevented the majority of honorable citizens in their areas of control from celebrating Eid Al Fitr and stormed a number of mosques and arrested citizens in Sanaa, Dhamar, Hajjah, and Ibb who refused to comply with their decision to postpone the celebration,” Yemen’s Minister of Information, Moaamar El Eryani, said on Twitter.
Yemen has been dragged into a civil war since 2014 after the Iranian-backed rebels seized its capital, Sanaa, and forced out its internationally recognised government.