Roads in and around Taizz, Yemen’s third largest city, have been blocked by rebel forces since 2015 in violation of international humanitarian law, provoking ire from a coalition of 15 human rights organizations who banded together Monday to call for meaningful action in the region to ensure the free flow of medication, food, and other essentials.

The blockades are attributed to the Houthis, a Zaydi Shiite rebel movement that has been engaged in active conflict against Sunni-majority Yemeni authorities since 2004, according to the Wilson Center, which notes the Iranian authorities are widely accused of backing the group.

Radhya Al-Mutwakel, the chairperson of one of the participating organizations, Mwatana for Human Rights, said in a statement:

The siege of Taizz has become nothing more than a card on the negotiating table. Civilians are paying a high cost to exercise their right of movement and access basic needs such as food, water and basic materials. The Ansar Allah armed group (Houthi) should immediately end undue restrictions on movement by opening major roads and allowing all Yemeni civilians to travel freely throughout their country.

Michael Page, deputy Middle East and North Africa director at Human Rights Watch, also a signatory to the initiative, said:

Houthi restrictions have forced civilians to use dangerous and poorly maintained mountain roads that are the only connection between Taizz city’s besieged population and the rest of the world. Opening the main roads would help immensely to alleviate the suffering of a population that has been in near-total isolation for seven years.

Under international humanitarian law, parties to a conflict are required to “allow and facilitate rapid and unimpeded passage of humanitarian relief for civilians in need, which is impartial in character and conducted without any adverse distinction, subject to their right of control.”

The Universal Declaration of Human Rights further states: “everyone has the right to freedom of movement and residence within the borders of each state.”

Since 2015, roads in and around the city have remained blocked, impeding access to food, medication, and other essential resources. Despite various efforts by international organizations and human rights advocates over the past seven years, progress has yet to be made, prompting human rights groups to band together to call for action.

Signatories of the initiative include: the Abductees’ Mothers Association, Amnesty International, Bridges for Yemen, the Cairo Institute for Human Rights Studies, the Campaign Against Arms Trade, the Global Centre for the Responsibility to Protect, Human Rights Watch, the Musaala Organization for Human Rights, Mwatana for Human Rights, PAX for Peace, the Project on Middle East Democracy, the SAM Organization for Rights and Liberties, the. Sheba Youth Foundation, Saferworld, and the Watch for Human Rights.