CAIRO (AP) — The U.N. migration agency Monday urged Yemen’s Houthi rebels to allow access to dozens of migrants injured in a fire at an overcrowded detention center in the capital.

Some 900 migrants, most of them from Ethiopia, were detained at a facility inside the Passports and Naturalization Authority complex in Sanaa, which is controlled by the rebels, when the fire took place, the International Organization for Migration said.

More than 170 migrants were injured, including over 90 seriously, the IOM said. At least eight people were announced dead Sunday, but the actual death tall remained unconfirmed since IOM did not have access to injured migrants at hospitals, it said.

“As many migrants are in critical condition, their health needs must be an urgent priority. We are facing challenges accessing the injured due to an increased security presence in the hospitals,” said Carmela Godeau, the agency's regional director for the Middle East and North Africa region.

A spokesman for the rebels was not immediately available to comment.

Despite its yearslong conflict, Yemen remains a transit point for tens of thousands of migrants desperate to find jobs as housekeepers, servants and construction workers in Saudi Arabia.

A U.N. official estimated Sunday that there were over 700 migrants at the center, most of whom were arrested in the northern province of Saada while trying to cross into Saudi Arabia.

The cause of the fire, which broke out at a hangar near the main building of the detention center, remined unclear, the IOM said. There were more than 350 people in the hangar area at the time of the fire, it added.

Some 138,000 migrants embarked on the arduous journey from the Horn of Africa to Yemen in 2019, but this number decreased drastically to 37,000 last year because of the coronavirus pandemic. Over 2,500 migrants reached Yemen from Djibouti in January, according to IOM.