Iran has accused its enemies, including the United States and Saudi Arabia, of being behind the unrest that it says has led to dozens of deaths, mostly among demonstrators but also among the security forces.

"I would like to say to Saudi Arabia that our destiny and that of other countries in the region are linked to each other because of us being neighbours," its intelligence minister, Esmail Khatib, said on Wednesday.

"For Iran, any instability in the countries of the region is contagious, and any instability in Iran can be contagious to the countries of the region," he said, quoted on the website of Iran's supreme leader Ayatollah Ali Khamenei.

"The Islamic Republic of Iran has so far adopted strategic patience but it cannot guarantee that it will maintain this strategic patience if hostilities against it continue," the minister added.

"If the Islamic republic decides to punish these countries, their glass palaces will collapse and they will no longer enjoy stability."

Last month, Iran accused the CIA and its counterparts in Britain, Israel and Saudi Arabia of "plotting" against it.