The ammunitions had been seized in 2009 from a cargo ship bound for Syria, and were awaiting disposal. The explosion severely damaged hundreds of buildings in Zygi and the nearby Vasilikos power station, Cyprus' largest one, causing widespread disruption in the supply of power to the island.
As a result of the incident, demonstrations were held in the capital Nicosia by angered citizens, leading to the resignation of the Cypriot Defence Minister and the Commander-in-Chief of the Cypriot National Guard.
The explosion was the worst peacetime military accident ever recorded in Cyprus, and is ranked as the fifth largest non-nuclear human-induced explosion in history, with a yield of approximately 2 to 3.2 kilotons.
In open storage on the base were 98 containers of 120 mm, 122 mm, 125 mm, and 160 mm high explosive artillery shells, 7.62 mm shell casings, compressed gunpowder, silver dollar-sized slugs[quantify], primers, and magnesium primers that had been seized by the United States Navy in 2009 after it intercepted a Cypriot-flagged, Russian-owned vessel, Monchegorsk, travelling from Iran to Syria in the Red Sea. According to leaked US cables through WikiLeaks, released in 2011, the US through Hillary Clinton exerted pressure on Cyprus to confiscate the shipment. The ship was escorted to a Cypriot port and the Cyprus Navy was given responsibility for the explosives, which it moved to the Evangelos Florakis a month later. At the time of the incident in 2011, the explosives had apparently been left in the open for over two years. The Cypriot government had declined offers from Germany, the United Kingdom and the United States to remove or dispose of the material, fearing an adverse reaction from Syria. The government had instead requested that the UN effect the removal, but claimed that its request had been rejected.