Yemen: The world's 'worst humanitarian crisis' in numbers

In this April 13, 2017, file photo, Yemenis present documents in order to receive food rations provided by a local charity, in Sanaa, Yemen. (AP / Hani Mohammed, File)

DUBAI, United Arab Emirates -- Yemen was already the poorest country in the Arab world before a Saudi-led coalition went to war with Iran-allied rebels in March 2015 in a failed bid to drive them from the capital and much of the country's north.

Since then the conflict has ground into a bloody stalemate, with more than 10,000 people killed and more than 2 million displaced.

The Saudi-led coalition has come under mounting international criticism for civilian casualties caused by airstrikes, the destruction of basic infrastructure and its blockade of key Yemeni ports, which are a lifeline for vital imports.

On Monday, Saudi Arabia announced $1.5 billion in new humanitarian aid for Yemen and vowed to expand the capacity of Yemen's ports to receive fuel, food and medicine, as well as establish "safe passage corridors" to ensure transportation of aid to non-governmental organizations inside Yemen.

The amount pledged represents about half that demanded by the UN in its latest humanitarian appeal. The conflict has fueled what UN agencies say is the "worst humanitarian crisis in the world."

Here's a look at the war's staggering toll in numbers: