The humanitarian situation has been growing ever worse in northern Yemen for months, with a Saudi blockade keeping aid out of the only port still controlled by the Shi’ite Houthis. The UN has been trying to get emergency aid into the capital city of Sanaa through the airport, but that seems to be no easier.

That’s because UN officials revealed today that Saudi Arabia is preventing, as part of the blockade, any shipments of jet fuel into Sanaa, meaning there’s no way for the UN planes to fly in, deliver aid, and still have enough fuel to fly out again.

UN officials warn the situation is increasingly bleak, with no real ability to get vital aid into parts of the country that are afflicted with a huge cholera epidemic, and are now on top of that facing an outbreak on meningitis.

The Saudis have been very heavily limiting aid to the north in recent weeks, blockading shipments of fuel for electricity generators last week, and also barring a UN aid flight before that because BBC journalists were on board.

A country that imports more than 90 percent of its food in peacetime, the Saudi blockade has had a terrifying impact on Yemen, raising growing concerns from human rights groups that they’re using access food and medicine as weapons of war.