Sunni insurgents led by Al-Qaeda offshoot the Islamic State of Iraq and the Levant (ISIL) have captured three strategic towns in western Iraq and the first border crossing with Syria.
The capture by ISIL (also known as ISIS) of Rawah on the Euphrates River and the nearby towns of Rutba and Anah in Anbar province on June 21 appeared to be part of a march toward a key dam in the city of Haditha, which has a hydroelectric power station.
Militants were also reportedly in full control of the Al-Qaim border crossing with Syria.
An Iraqi intelligence official, speaking to the Reuters news agency on condition of anonymity, said army troops withdrew from Rawa, Anah, and Rutba after ISIL militants started to attack those towns late on June 21.
"They [ISIL] took Ana and Rawa this morning without fighting," the official said.
On June 21, thousands of Shi'ite fighters loyal to the influential cleric Moqtada al-Sadr staged a parade through Baghdad.
The show of force of fighters accompanied by military hardware is likely to raise sectarian tensions at a time when Prime Minister Nuri al-Maliki's government is under pressure to rally the country together against the extremists.
In Iran, where the government is backing the Iraqi government against ISIL, President Hassan Rohani said in a speech that those who "spend their money and oil dollars to help terrorists today [should] know that tomorrow is your turn."
Rohani was speaking on June 22 at the opening of a two-day international conference on the Second Shi'a Imam Hasan.
He warned unspecified countries that their support for militant groups would lead to their own downfall.
"Do not think that these wild terrorists who you directed toward others [will not harm you]," Rohani said. "Tomorrow will be your turn. Stop it. Stop the bloodshed."
Rohani called for unity between Shi'a and Sunnis who are "brothers."
"We Muslims must all stand against extremism and violence," he said.
With reporting by AFP, AP, and IRIN