Sadrist Movement and Saraya al-Salam have been on alert on Friday after the commander of Iran's Revolutionary Guard Corps, Qasem Soleimani threatened the movement's leader, Moqtada al-Sadr.
A member of the British House of Lords told BBC News that the United States has ordered Soleimani to leave Iraq immediately, pointing out that the U.S. will not be responsible for the protection of the Iranian official if he decided to stay in Iraq.
Soleimani has a notorious role in the Iraq-Iran War in the 1980s.
In 2012, he fought beside Syrian dictator Bashar al-Assad through thousands of terrorists sent to curb the Syrian revolution that erupted in 2011.
Moreover, he has a strong political clout in Iraq, Syria and other countries. It is widely thought he controls the political scene in Iraq.