"The judicial authorities have begun the procedures of the trial, and the judgements will be announced once they acquire the peremptory status," said coalition spokesman Turki al-Maliki quoted by the official Saudi Press Agency.

The Saudi-led military coalition -- which includes the United Arab Emirates -- intervened in the Yemen conflict on the side of the government in March 2015, shortly after Iran-aligned Huthi rebels seized the capital Sanaa.

Both the coalition and the rebels stand accused of actions that could amount to war crimes.

The cases which are being investigated include the 2016 deadly bombing of a hospital supported by Doctors Without Borders (MSF), in which 19 people were killed, the Saudi-based Arab News said.

The cases also involve a 2018 air strike on a school bus in Dahyan that killed at least 40 children and a raid on a wedding party the same year in the Huthi-controlled Bani Qais area of Hajjah province which left 20 dead.

Maliki, who was speaking at a press conference in London on Wednesday, said the Joint Incident Assessment Team (JIAT) -- which the coalition established but says operates independently -- has transferred files of the investigation results to the relevant countries.

The coalition was committed to holding responsible "violators... of international humanitarian law -- if any -- in accordance with the laws and regulations of each country in the coalition", Maliki added.

Tens of thousands of people, most of them civilians, have been killed and millions have been displaced in the conflict in Yemen, which the United Nations says is gripped by the world's worst humanitarian crisis.