At least eight migrants and guards were killed, and scores more injured, in a fire on Sunday at a holding facility in Yemen’s capital, the International Organization for Migration said.

“Eight people confirmed dead, the total death toll is reported to be much higher,” tweeted Carmela Godeau, IOM’s regional director for the Middle East and North Africa.

“IOM is responding particularly with emergency health care for over 170 injured, more than 90 of them are in a serious condition.”

Godeau said that it “remains unclear” how the fire at the centre in Sanaa started, adding: “This is just one of the many dangers that migrants have faced during the past six years of the crisis in Yemen.”

It is believed thousands of migrants are stranded in Yemen, where a years-long conflict has claimed tens of thousands of lives and displaced millions in what the UN calls the world’s worst humanitarian crisis.

Every year thousands of migrants make perilous boat journeys from the Horn of Africa to the war-torn nation, many with the aim of travelling overland to Gulf countries in search of work.

Last week, at least 20 people drowned after smugglers threw dozens of migrants overboard during a crossing between Djibouti and Yemen, according to IOM.