By Nathan Morley
This incident threatens to scupper current UN efforts to bring peace to the country.
The attack appears to have been well organised, with reports suggesting the drone exploded above a podium at al-Anad base, which is an important military facility.
At the time, senior officers were observing a parade of over 8,000 troops. Initial reports suggest at least six soldiers were killed.
A Houthi-run radio network claimed the rebels targeted personnel from the Saudi-led coalition, which support the government.
Yemen today is the home of the world's worst humanitarian crisis. It is estimated that more than 22.2 million people - or 75 percent of the population - is in need of humanitarian assistance. The conflict has left 2 million people displaced from their homes.
The civil war in Yemen began in 2014 when the rebels captured the capital Sanaa.