The Iranian media report did not give details, but Iran has carried out preparations to shift higher-grade enrichment to an underground facility near the holy city of Qom, offering the sensitive work better protection against any military attacks.

Controversy over Iran's uranium enrichment program has resulted in Western powers imposing increasingly tight economic sanctions on the Islamic Republic. Israel and the US say they have not ruled out military action if diplomacy fails to persuade Tehran to suspend its activities.

"If conditions require, we will move our uranium enrichment centres to safer places," the semi-official Mehr News Agency quoted Brigadier General Gholamreza Jalali as saying.

Western powers suspect Iran is trying to acquire the ability to produce nuclear weapons. Iran denies this, saying it is enriching uranium only for peaceful purposes such as power generation and medical use.       

Reuters