"A triangle was at work", comprised of the U.S., Zionists and a "dirty rich" country, Khamenei said. Reports say that at least 20 people, including civilians and policemen, were killed and dozens wounded during violent clashes between protesters and security forces that arrested some 3,700 demonstrators so far. "All of us must follow up", Mr Khamenei said.
Iranian Ayatollah Ali Khamenei's official Twitter account posted a string of 11 tweets on Tuesday, all of them criticizing what the revolutionary leader claimed was a USA -led conspiracy that had manifested itself in violent anti-government protests.
Demonstrations broke out across Iran last month fueled by anger at the lackluster economy and official corruption.
In a rare public appearance, the head of Israeli intelligence agency Mossad said the protests were due to Iranian President Hassan Rouhani's failure to improve people's economic or social circumstances, but he said they were unlikely to overthrow the establishment.
As well as Washington and London, Mr Khamenei blamed the violence on Israel, exiled dissident group People's Mujahedin of Iran and "a wealthy government" in the Gulf, a reference to Iran's regional rival, Saudi Arabia.
"It is true that the situation in Iran is critical, but not as much as some try to depict", he added, stressing that "the Iranian regime has sufficient political and security abilities to contain the situation". The Revolution politically eradicated the enemy from Iran.
Four days ago, Russian ambassador to the UN Vassily Nebenzia claimed that the United States is exploiting the protests in Iran in order to derail the landmark nuclear deal with the Middle East country.
"In my opinion, they are spontaneous protests that are neither prearranged nor financed by any foreign states".