At least thirty-one people were killed in airstrikes in Yemen on Saturday, according to the United Nations,

The victims of an apparent Saudi-led retaliation after Iran-backed Huthi rebels claimed to have shot down one of its jets.

The Tornado aircraft came down Friday in northern Al-Jawf province during an operation to support government forces, a rare shooting down that prompted operations in the area by a Saudi-led military coalition fighting the rebels.

The deadly violence follows an upsurge in fighting in northern Yemen between the warring parties that threatens to worsen the war-battered country’s humanitarian crisis.

“Preliminary field reports indicate that on 15 February as many as 31 civilians were killed and 12 others injured in strikes that hit Al-Hayjah area… in Al-Jawf governorate,” the office of the UN humanitarian coordinator for Yemen said in a statement.

The Huthi rebels released footage of what they called the launch of their “advanced surface-to-air missile” and the moment it struck the jet in the night sky, sending it crashing down in a ball of flames.

“The downing of a Tornado in the sky above Al-Jawf is a major blow to the enemy and an indication of remarkable growth in Yemeni (rebel) air defence capabilities,” Huthi spokesman Mohammed Abdelsalam tweeted.

In 2017, at least 21 people were killed and another seven wounded in an airstrike by the Saudi-led Arab coalition on a hotel in northern Yemen’s Sa’dah province controlled by the Houthi rebels.

The Arab coalition’s military intervention in Yemen began in March 2015 in support of the government led by President Abdu Rabu Mansour Hadi and against the Houthi rebels, who control the capital Sana’a and the wide stretches in the western part of the country.

The alliance of Arab and Sunni countries have previously been accused of bombing civilian targets including schools and hospitals, but it has denied intentionally targeting civilian infrastructure or property.

(With inputs from agency)