Children have been subject to a widespread and “shocking” scale of violence this year, the U.N.’s children fund said, as conflicts around the world have increasingly targeted and victimized the most vulnerable.

As violence spread across the Middle East, Africa, Myanmar, and eastern Ukraine, children have found themselves on the front lines, used as human shields or recruited as fighters by armed or extremist groups. They have been subject to sexual violence, forced marriage, abduction, and enslavement, UNICEF said in a press release. Even after fighting has stopped, UNICEF said, children often continue to suffer from malnutrition and trauma, and lack access to adequate medical facilities, which are often destroyed in war.

“Children are being targeted and exposed to attacks and brutal violence in their homes, schools and playgrounds,” said Manuel Fontaine, UNICEF Director of Emergency Programmes. “As these attacks continue year after year, we cannot become numb. Such brutality cannot be the new normal.”

The report singled out several conflict hotspots in 2017, including western Africa, where Boko Haram forced 135 children into suicide bombings, a fivefold increase over last year. In Iraq and Syria, children have reportedly been used as human shields, maimed and killed, or trapped in besieged areas under intense bombardment as fighting between Syrian rebel forces and forces loyal to to President Bashar al-Assad entered its sixth year.

Read more: Rohingya Refugees: Myanmar’s Crisis Is Bangladesh’s Burden

In civil-war wracked Yemen, fighting and a Saudi Arabia-imposed blockade has created a humanitarian catastrophe, with 5,000 children confirmed dead or injured and 1.8 million children suffering from malnutrition. A cholera epidemic is believed to have surpassed one million cases, with the outbreak killing more than 2,000 people.

Children account for more than half of the 655,000 Rohingya refugees who have fled violence in western Myanmar since August 2017. In sprawling refugee camps in Bangladesh, they are particularly vulnerable to malnutrition and disease, including a diphtheria outbreak that has already claimed 22 lives, according to the U.K.’s Department for International Development.

The report also highlighted concerns about child recruitment and abduction in Somalia and Central African Republic, while in the Democratic Republic of the Congo, 850,000 children have been displaced by fighting. In eastern Ukraine, 220,000 children are endangered by landmines and other unexploded ordinances along a 310 mile de facto border that is “becoming one of the most mine-contaminated places on earth.”

UNICEF called on all parties involved in conflict to “abide by their obligations under international law” and “immediately end violations against children and the targeting of civilian infrastructure, including schools and hospitals.”

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Write to Eli Meixler at eli.meixler@time.com.