Iran's foreign minister, blaming Israel for what Tehran called a 'terrorist attack' on its Natanz nuclear enrichment facility, has vowed to take revenge: 'The Zionists did this because of our progress in the way to lift sanctions; they have publicly said that they will not allow that. But we will take our revenge upon them'. Natanz was hit by a cyber-attack just a day after Tehran unveiled new uranium enrichment centrifuges there. Centrifuges are used in the process to create enriched uranium, which is used to make reactor fuel but can also be used to create nuclear weapons. Israeli media said its Mossad spy agency was responsible for the attack.