It coincides with a UN report that says up to 14 million people are in danger of famine in the region, the number at risk rising sharply following an aid blockade imposed on Yemen by the Saudi and Emirati-led coalition just over a year ago.
Hopes of a ceasefire in the brutal conflict appear to have been dashed after fighting resumed in the port city of Hodeidah between the Saudi-UAE coalition and Houthi rebels.
The military alliance – led by Riyadh – conducted more than 10 airstrikes on rebel-held positions on Tuesday, despite having ordered a halt in its offensive last week amid pressure from the West.
Using data compiled by the UN, Save the Children evaluated mortality rates for untreated cases of Severe Acute Malnutrition (SAM) in children under five years in Yemen.
The charity calculated that even by a conservative estimate approximately 84,700 children with SAM may have died between April 2015 and October 2018.
“We are horrified that some 85,000 children in Yemen may have died because of extreme hunger since the war began. For every child killed by bombs and bullets, dozens are starving to death and it’s entirely preventable.
“Children who die in this way suffer immensely as their vital organ functions slow down and eventually stop. Their immune systems are so weak they are more prone to infections with some too frail to even cry. Parents are having to witness their children wasting away, unable to do anything about it.
“Save the Children has provided food for 140,000 children and treated more than 78,000 children for malnutrition since the start of the crisis. Despite the challenges, we’re saving lives every day.”
Britain has drafted a UN Security Council resolution calling for a halt to fighting in Hodeidah, a stop to attacks on populated areas across Yemen and on other countries in the region, and more aid funding.
Saudi Arabia and the coalition it leads first intervened in Yemen in 2015, with the aim of restoring its internationally-recognised government that had been ousted from the capital of Sanaa the year before.
Following the latest renewal of hostilities, a Saudi humanitarian official said the coalition was willing to contribute $500m (£3.9m) to a new aid programme for Yemen.