Four children and six troops were killed when a ballistic missile ripped through a military parade for a Yemeni separatist group that is backed by the United Arab Emirates, a spokesman said.
The attack took place at the end of an event the separatists, known as the Resistance Forces, were holding for new recruits at a football field in the capital of southern Dhale province, said Maged al-Shoebi, a spokesman for the group.
The southern separatists are allied with the Saudi-led coalition that has been fighting Yemen’s Houthi rebels. Mr al-Shoebi blamed Houthi rebels for the attack.
But the UAE-backed southerners are at odds with Yemen's internationally recognised government, which is more closely allied with Saudi Arabia.
Cracks within the anti-Houthi bloc have widened over the past several months.
Footage circulated online of Sunday’s attack showed a hole in a stage at the edge of the field, apparently from an explosion, while other footage showed bodies on the ground.
More than 21 people, including civilians, were injured in the blast, Mr al-Shoebi said, blaming the Houthis for the attack.
The rebel group did not immediately comment.
The Houthis have been trying to wrest Dhale province from the southern separatists for years, but without much progress.
The conflict in Yemen began with the 2014 takeover of Sana'a by the Houthi rebels. They drove out the government of president Abed Rabbo Mansour Hadi, forcing him to flee to the south and eventually to Saudi Arabia, which entered the war in 2015.
The fighting in the Arab world’s poorest country has killed more than 100,000 people and left millions suffering from food and medical shortages.
The conflict has also pushed the country to the brink of famine. – AP