Refugees flee to Baghdad as Shiites prepare to retake Ramadi from Islamic State

RAMADI, Iraq, May 20 (UPI) -- An estimated 25,000 people have fled Ramadi, Iraq, on Wednesday as thousands of Shiite militants amass in the suburbs to dislodge Islamic State insurgents who conquered the city.

After heavy fighting against government troops in one of the few towns the Iraqi government controls, in mostly Sunni Anbar province, IS overran Ramadi Sunday. The IS killed at least 500 people in the invasion, and Monday went door-to-door in search of government sympathizers. Refugees are leaving, with many heading for Baghdad, 78 miles away. "Nothing is more important right now than helping the people fleeing Ramadi. They are in trouble and we need to do everything possible to help them," said Lise Grande, the Iraq's United Nations Humanitarian Coordinator.

At least 3,000 Shiite have arrived and are massing around Ramadi at the request of the Iraqi government, to take back the city of about 500,000. Local Sunni leaders are suspicious of the Iran-backed Shiites and would prefer the government arm and train local volunteers for the fight.

Shiites are responsible for the recapture of Tikrit, early in May, but some fighters were engaged in looting and violence after the success, Ramadi leaders claim.

"There are people in our government who see any involvement of Iran as anathema. There are others who say the Shiite involvement will promote sectarian violence. There are others who say that's not true," a U.S. official told Al Jazeera.

Calling on Shiites to repel IS after the fall of Ramadi is an indication Iraq's Sunni strategy has failed. The inability of a Sunni-led force to keep Ramadi from IS hands has reopened grievances between Iraq's two major Islamic sects.