A Human Rights Watch report released on 9 May has concluded that a blast which killed 15 Yemeni school children in April this year was caused by a Houthi-controlled warehouse that stored volatile material which caught fire and detonated in Yemen’s capital Sanaa. The massive blast injured more than 100 children and adults in the residential Sawan neighborhood.

“The Houthi authorities need to provide credible information and stop storing large concentrations of volatile materials in densely populated areas,” said Radhya al-Mutawakel, the chairperson of Mwatana for Human Rights. “The Houthis played a role in the tragedy and should hold responsible officials to account and provide compensation to victims.”

Of the 15 children killed, the organisation Mwatana for Human Rights identified the names and ages of 10 girls and a boy who died at two schools, and 17 girls and 12 boys who were wounded, most of them 11 or 12 years old. At least 45 children were wounded, 5 critically, as well as at least 58 adults.

At least 6,800 civilians have died in Yemen’s four-year civil war. Some 10,700 more have been injured in the fighting, according to the UN. Many thousands more have died from preventable causes such as malnutrition, disease and poor health.

During the current conflict, one in five schools in Yemen has been closed, damaged by attacks, or used for military purposes, according to UNICEF, and throughout the war, the Houthis have been accused of using child soldiers as well as torturing and killing journalists and critics, siphoning off aid supplies, placing mines around ports, using civilian infrastructure as a shield for military activity and persecuting the country’s Jewish and Baha’i minorities.

Both Hezbollah and Iran have increased their provision of guns, missiles, military training and funds for the Houthi war effort since 2014, happy to see their Saudi enemies expend soldiers and money on the Yemeni stalemate.

Yet five months after the highly praised handshake between the different sides of the conflict at the Yemen summit in Stockholm, UN envoy Martin Griffiths remains optimistic about the ongoing stalemate. Briefing the Security Council in April, he praised both sides for accepting phase one of the agreed-upon plan for the redeployment of Houthi and government forces from the key port city of Hodeidah.

“It has been, as we all know, a long and difficult process. I am happy to announce to you Mr. President that both parties have now accepted the detailed redeployment plan, prepared by General Michael for phase one of the redeployments in Hodeida. I am grateful, as I’m sure we all are, to both parties […] for the constructive engagement which has allowed us finally to reach this point,” he said.

The Houthi movement was founded in the 1990s by Hussein Badreddin al-Houthi, a member of Yemen’s Zaidi Shia minority, which makes up about one-third of the population. Hussein was killed by Yemeni soldiers in 2004, and the group is now led by his brother Abdul Malik.

The Zaidis, once a powerful force in north Yemen, were sidelined during the 1962-70 civil war and then further alienated in the 1980s as Salafist Sunni ideals gained prominence across the border in Saudi Arabia, which exported the ideology to Yemen. In response, Zaidi clerics began to militarise their followers against Riyadh and its allies.

The intermittent insurgency gained support from Shia Yemenis fed up with the corruption and cruelty of the long-time authoritarian president and Saudi ally, Ali Abdullah Saleh, particularly during the aftermath of 9/11 and the US invasion of Iraq.

Popular protests and several assassination attempts forced Saleh to resign in 2012. The Houthis, as one of the only revolutionary groups with military experience, steadily gained control of territory outside their northern heartlands.

As they grew more powerful they pulled out of transition talks aimed at creating a new and stable Yemeni government after Saleh’s downfall. In 2015 they allied with their former enemy Saleh, seizing the capital, Sana’a, and overthrowing the new president, Abd Rabbu Mansour Hadi. After they seized Sana’a in 2015, forcing Hadi to flee, the exiled Yemeni government asked its allies in Saudi Arabia and the UAE to launch a military campaign to drive out the Houthis.