AL-MUKALLA, Yemen: The Iran-backed Houthi militia in Yemen were wholly responsible for conditions in an overcrowded migrant detention center in Sanaa where dozens died in a fire, the UN migration agency said on Sunday. “Conditions in the holding facility, which was three times over capacity, were inhumane and unsafe,” said Antonio Vitorino, director general of the International Organization for Migration. The agency chief rejected attempts by the Houthis to deflect blame on to the UN, and he denied the militia’s claims that his organization had neglected the center and failed to install safety equipment, and had refused to send the migrants back to their home countries. “The IOM does not establish, manage or supervise detention centers in Yemen or anywhere else in the world,” he said. “Our teams provided migrants essential services like food, healthcare and water that they otherwise would not have received.” Dozens of local rights groups, activists and government officials have called for an international investigation into the deadly fire on March 7. They accuse the Houthis of hastily burying the dead and intimidating survivors and their families to hide the truth. The official death toll from the blaze is 43, all migrants from Ethiopia, Eritrea, Djibouti, Somalia and Sudan. Many survivors are being treated in hospital for burns and the effects of smoke inhalation. However, the true number of deaths is thought to be far higher, possibly in the hundreds. Under local and international pressure to disclose the number of dead, the Houthis forced leaders of east African communities in Sanaa to issue a statement that blamed the UN migration agency. Dozens of African migrants took part in a protest on Sunday outside the offices of the UN High Commissioner for Refugees in Aden to demand information about the dead, improvements in their conditions, and for those responsible for the fire to be brought to justice. “We are so tired, young people died for no reason. There are still lots of injured people in hospital,” one migrant said. A survivor displayed his injuries from the fire and other migrants showed graphic images of charred corpses.