Sabotage or attempted theft followed after explosions at a weapons depot. It was caused by high temperatures and poor storage conditions and killed 103 people.
The commission, led by Judge Antonio Pale, also listed a lack of Defense Ministry inspections of the warehouse as a contributing factor.
The March 22 explosions - of grenades, rockets and artillery and mortar shells - were so intense that fire fighters were unable to get close enough to fight the blaze. The blasts caused severe damage over a wide area of suburban Maputo.
President Armando Guebuza, who said he supported the report's findings, has instructed the government to destroy all obsolete weapons throughout the country.
He also ordered all weapons depots moved to remote locations as soon as possible.
On Wednesday, the government announced it would offer the equivalent of US$12 million (9 million EUR) in compensation to help victims rebuilt homes. Hundreds made homeless by the March 22 explosions have since been living with relatives or in tents.