More than 100 people were killed and dozens wounded in a missile and drone attack blamed on Huthi rebels in central Yemen, officials said Sunday.

Saturday’s strike follows months of relative calm in the war between the Iran-backed Huthis and Yemen’s internationally recognized government, which is supported by a Saudi-led military coalition.

The Huthis 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, military sources told AFP.

“We strongly condemn the terrorist attack on a mosque by the Huthi militias… which left more than 100 dead and dozens injured,” the Yemeni foreign ministry said on Twitter.

An army spokesman said that the dead included soldiers and civilians, and that the Huthis would face a “ruthless” retaliation to the strike.

The victims were transported to a Marib city hospital, where a medical source earlier gave a toll of 83 dead and 148 injured.

Death tolls in Yemen’s grinding conflict are often disputed, but the huge casualty list in Marib represents one of the bloodiest single attacks since the war erupted in 2014 when the rebels seized Sanaa.

The Huthis did not make any immediate claim of responsibility.

Saudi-owned Al-Hadath television broadcast a video that it said showed the gruesome aftermath of the attack.

Body parts can be seen on the floor among shredded debris. Blood is pooled on the carpet and spattered against the walls.

The drone and missile strike came a day after coalition-backed government forces launched a large-scale operation against the Huthis in the Nihm region, north of Sanaa.

Fighting in Nihm was ongoing on Sunday, a military source said according to the official Saba news agency.

“Dozens from the (Huthi) militia were killed and injured,” the source added.