Foreign envoys to Yemen and rights groups have strongly condemned a fire at a Houthi-controlled migrant center and demanded that the rebels give investigators access to the site and the wounded.

The UK’s ambassador to Yemen, Michael Aron, on Friday condemned the incident and called for an immediate and objective probe and unhindered access to the injured migrants.

“Appalled by fire at Houthi-controlled migrant center in Sanaa,” he tweeted. “OHCHR & humanitarian agencies need immediate, unrestricted access to site & those injured. A credible, transparent, independent investigation must be carried out, including a full account of those killed & injured.”

Aron blamed the Houthis’ brutal treatment of migrants, saying it had led to the fire and loss of life. “It is the Houthis inhumane treatment of migrants — including the creation of overcrowded conditions at the center — that led to this terrible loss in human life. It is imperative that the Houthis change their policies toward migrants & provide them the basic dignity they deserve,” he said.

Activists and rights groups in Yemen also called for an international probe and for the perpetrators to be tried in international courts.

Women Solidarity Network accused the militia of using live bullets and explosive devices to suppress migrant protests and demanded the UN protect survivors from Houthi intimidation.

“We urge international organizations, including the United Nations, to provide protection to the migrants who have been hospitalized,” said the group. “Our sources raised the alarm that the Houthis were promising migrants in hospitals the issuance of cards in return for their silence. As per information collected from witnesses, Houthis rounded up illegal African migrants, including children, from their homes to force them into recruitment as fighters to send them to conflict fronts.”

The Geneva-based SAM Organization for Rights and Liberties said that, based on interviews with some survivors, the Houthis had used force to end a strike by migrants who were protesting against cruel treatment, extortion and poor conditions inside the detention center.

“The Houthis were directly and consistently responsible for the killing and injury of approximately 450, mostly Ethiopian, migrants in a detention center, on 7 March, 2021, in a fire caused by bombs apparently fired by Houthi forces,” it said.

A social media campaign has been launched to bring global attention to the Houthis’ role in the fire and to keep the tragedy high on the international agenda to prevent the Houthis from committing other atrocities.

“This is a crime against humanity, values and morals. And is only committed by terrorist, barbaric and nihilist groups,” tweeted Yemeni journalist Abdullah Esmail.

Yemeni government forces on Friday announced seizing control of several locations in the northern province of Hajja after a fresh assault against the Houthis.

The Defense Ministry said that troops had liberated a large swathe of land in Abes district after fighting with the militia.

In Taiz, troops consolidated their gains in Al-Kadaha, west of Taiz, after opening a new lifeline road to the besieged city.

Local army commanders said the main objective of current military operations in Taiz and Hajja was relieving Houthi military pressure on troops in the central city of Marib.