The United Nations Sunday condemned the missile attack on a government military training camp in Yemen, in which at least 80 soldiers were killed and 130 others wounded.

The UN Special Envoy to Yemen, Martin Griffiths, said that the attack could derail a fragile political process that aims to calm the almost five-year-old war.

“I have said before that the hard-earned progress that Yemen has made on de-escalation is very fragile. Such actions can derail this progress,” Griffiths said.

The Houthi fighters attacked a mosque in a military camp in the central province of Marib — about 170 kilometres (105 miles) east of the capital Sanaa — during evening prayers, news agencies reported.

Meanwhile, the UN Envoy urged all parties to “stop the escalation” and focus energies into policy instead.

“The negotiation tables are more effective than battlefields in resolving the conflict,” Griffiths said.

Yemen’s exiled President, Abdu Rabu Mansour Hadi condemned the attack adding that the attack “confirms without doubt that the Houthis have no desire for peace.”

The Houthi movement has not claimed the responsibility for the attacks so far. Yemen has been mired in almost five years of conflict since the Iran-aligned Houthi movement ousted Hadi’s government from power in the capital Sanaa in late 2014, prompting intervention in 2015 by a Saudi-led military coalition in a bid to restore his government.

The United Nations has been trying to re-launch political negotiations to end the war and, separately, Saudi Arabia has been holding informal talks with the Houthis since late September 2019 about de-escalation. This has seen violence decrease on a number of fronts in recent months.