"According to preliminary data on the Houthis' explosive-laden UAV attack, six soldiers were killed and 14 injured", the source said Thursday.
The Yemen government and allies Saudi Arabia and the United Arab Emirates (UAE), however, are complaining that the Houthis violated the ceasefire and the rebels show no signs of getting ready to withdraw from their positions at Hodeidah.
The parade was taking place inside a military base in the Anad district when a loud explosion rocked the area, witnesses said, adding high-ranked officials, including Yemen's deputy chief of staff, were wounded in the attack.
Yemen has always been engulfed in a state of war between the internationally backed government and the Houthi rebels. The U.N. humanitarian aid chief Wednesday accused the rebels of blocking humanitarian supplies traveling from areas under their control to government-held areas.
The use of a drone also raised new concerns over Iran's influence in the conflict.
The attack also raised new questions about Iran's alleged role in arming the Houthis with drone and ballistic missile technology, something long denied by Tehran despite researchers and United Nations experts linking the Yemeni rebel weapons to the Islamic Republic.
Those drones have in the past been flown into the radar arrays of Saudi Arabia's Patriot missile batteries, according to the research group Conflict Armament Research, disabling them and allowing the Houthis to fire ballistic missiles into the kingdom unchallenged.
Houthi media quoted its military describing the drone as a new variant of its Qasef, or "Striker", drone. The Qasef-2K has been created to explode at a height of 20 metres (about 65 feet) and rain shrapnel on its target, according to the Houthis.
For its part, Iran repeatedly has denied supplying the Houthis with drone or ballistic missile technology. The Ababil-T can deliver up to a 45-kilogram (100-pound) warhead up to 150 kilometres (95 miles) away.
Such drones also remain hard to shoot down with either light or heavy weapons fire.
Coalition forces a year ago also showed journalists a Houthi "drone boat" filled with explosives that failed to detonate. Iraqi forces learned while driving out the Islamic State group from northern Iraq, where the extremists would load drones with grenades or simple explosives to target their forces.
"They're like slow missiles".
The Qatef-2K, which the Houthis said they used in Thursday's attack, similarly resembles the Iranian designs. They have received logistical and intelligence support from the US, UK and France. "They needed to specifically know when those guys are in the stands to be able to target".