The blast happened at about 09:55 BST. A Port of Tilbury spokeswoman confirmed a "major incident" had taken place last Friday, and the ambulance service said one person had been treated for smoke inhalation, reports theBBC.
Crews found grain on fire inside the plant and were able to remove unaffected grain so it did not ignite.
"About six of the silos exploded, the tops are all gone," Tony Coughlin, who lives close to the port, told the BBC.