AMMAN, Three years of war, coupled with decades of chronic underdevelopment in Yemen, has resulted in 11 million children plagued by malnutrition and disease, and facing acute humanitarian needs, a senior official of the United Nations Children's Fund (UNICEF) said, here, Sunday.

According to Geert Cappelaere, UNICEF's regional director for the Middle East and North Africa, Yemeni children have been killed or seriously injured, at a minimum rate of five per day in 2017 alone. The outbreaks of cholera and diphtheria have also claimed hundreds of children's lives.

"Much more attention is needed to (be paid to) the situation in Yemen. This has been rightly described as one of the worst humanitarian crises the world has ever known," Cappelaere told reporters.

Yemen, already one of the poorest countries in the Middle East, has been devastated by a civil war since 2015, when what was supposed to be a peaceful transition of power from the longtime president, Ali Abdullah Saleh, to his deputy Abdrabbuh Mansour Hadi, evolved into a regional conflict.

With the Houthi rebel group joining the fight, as well as, an intervention by the coalition troops, led by Saudi Arabia, Yemen has been dragged into a civil war which shows no sign of abating until today.

"It is fair to say today that, every single girl and boy in Yemen is facing acute humanitarian needs," Cappelaere said, adding that, the war and underdevelopment had done "unfortunately nothing good" for the children.

The official said, there were 200,000 children suffering from severe malnutrition in 2015, already one of the highest numbers in the world by then. Yet, the number has doubled in three years' time till now, according to Cappelaere.

Acknowledging that the cholera outbreak in Yemen had been stemmed and that a vaccination campaign against diphtheria had been conducted in the past two weeks, the official said, health and humanitarian workers both in Yemen and from the international community "should pause for a moment to be proud" of these achievements.

"But let's not fool ourselves," Cappelaere added, warning, a comeback of the cholera epidemic, following the start of the rainy season in a few weeks. He called for "huge and immediate investments" to prevent the possible outbreak.

Further elaborating on the worsening humanitarian situation in the war-torn country, Cappelaere said, close to two million Yemeni children are deprived of education, and that a large proportion of girls are forced to marry at early ages -- 75 percent of them before the age of 18 and half younger than 15.

The official called for an immediate cease of war and urged authorities in all parts of the country, to allow entry of humanitarian assistance without preconditions.