A missile fired by the Iran-aligned Houthi group struck a military parade in Yemen's town of al-Dhalea, killing at least six people and injuring others, government-allied southern separatist forces who control the area said on Sunday.
No claim of responsibility was made and Houthi media did not immediately comment on the blast or accusation.
The missile blast struck a parade ground where a military graduation for Security Belt forces had just finished, statements from the Security Belt group and the al-Dhalea southern separatist forces said.
The Security Belt forces are part of a government-aligned southern separatist front in south Yemen which favours the creation of an independent state.
They are also backed by the United Arab Emirates in a fight against Yemen's Iran-aligned Houthi group.
Witnesses told Reuters that the blast occurred near a guest platform during the parade, causing injuries and deaths. They reported seeing bodies at the scene.
Pictures from the scene showed a blast hole in the concrete floor of an outdoor square.
Six people died and between 15 and 25 were injured, according to local health authority figures quoted by the local forces' spokesman.
Yemen has suffered from almost five years of conflict since the Houthi movement ousted President Abd-Rabbu Mansour Hadi's government in late 2014. The coup drew military intervention in 2015 by a Saudi-led coalition, which includes the UAE, trying to restore Hadi's internationally recognized government.
The town of al-Dhalea is controlled by southern separatist forces. It lies on the main south-to-north road linking the southern port of Aden - controlled by Hadi's government - to the Houthi-controlled capital, Sanaa.
A contested frontline runs across al-Dhalea province.
In August the Houthis claimed responsibility for a missile and drone attack on a parade in Aden, the seat of the internationally recognised government, killing around 36 people including a prominent commander.