Yemen's Houthi rebels say they have killed the man they hold responsible for the recent assassination of their leader's brother, adding that the man was a spy for archenemy Saudi Arabia.

The rebel-run authorities in the capital, Sanaa, released a statement on Wednesday evening, saying their fighters killed 54-year-old Mohamed Ali Qayed Dawy in an operation in central Marib province.

Marib is controlled by forces loyal to Yemen's Saudi-backed government.

The Houthis last month said an assassin killed their leader Abdel Malek al-Houthi's brother, Ibrahim al-Houthi.

Since 2015, a Saudi-led coalition has been waging war against the Houthis on behalf of Yemen's internationally recognized government.

The coalition's spokesman, Col. Turki al-Maliki, has denied allegations about the kingdom's involvement in Ibrahim's killing and blamed it on internal disputes among the Houthis.

AFP