Police and soldiers were guarding the warehouse in Alangalang town, 17 kilometres from Tacloban, but were overpowered by the crowd, who carted off more than 100,000 bags of rice, Estoperez added.
"There must have been so many people to carry away so many bags of rice," he said, adding that each bag weighed 50 kilograms.
"Our staff were there but they could not do anything without risking their safety."
The United Nations fears that 10,000 people may have died in Tacloban alone when Super Typhoon Haiyan, one of the strongest storms ever recorded, smashed into the Philippines' central islands on Friday.
The typhoon left huge areas isolated and hundreds of thousands homeless and hungry.