By Ahmed Rasheed
BAGHDAD (Reuters) - A suicide bomber killed eight people including six soldiers on Tuesday in the northern Iraqi city of Baiji where government forces are trying to reassert control to break an Islamic State siege of the country's largest refinery nearby.
The bomber targeted a crowd gathering around soldiers who had retaken parts of the city center, Baiji Mayor Mohammed Mahmoud told Reuters. Security officials said two civilians and six soldiers were killed.
Islamic State insurgents seized much of northern Iraq five months ago in an offensive in which they took Baiji and surrounded the oil refinery, halting production and besieging a detachment of government troops there.
U.S. air strikes have slowed down the radical Sunni Muslim insurgents and enabled Iraqi security forces to make some gains.
Iraqi security forces have used helicopters to attack Islamic State fighters ringing the refinery.
Months of operations have failed to rescue comrades trapped inside and ensure the strategic site will not fall into the hands of Islamic State, who have used oil and fuel to fund their self-proclaimed religious caliphate.
Iraqi oil industry officials estimate Islamic State is making multimillion-dollar profits from the illegal trade.
Islamic State's presence in Iraq has fueled sectarian violence which recalls the height of a civil war in 2006-2007. It also controls parts of neighboring Syria.
Earlier on Tuesday, Iraqi Prime Minister Haider al-Abadi said he intends to remove concrete barriers from Baghdad despite little sign of a respite from car bombs they were designed to thwart.
He also said he would accord a greater role to the Interior Ministry in securing the capital of 7 million people, suggesting he aimed to reduce the army's presence.
Baghdad, like the rest of Iraq, faces suicide and car bombings. Some are claimed by Islamic State militants.
Iraqi security forces have been fighting for weeks to contain and push back Islamic State fighters from territory to the south, west and north of the capital.
Similar pledges were made by former prime minister Nuri al-Maliki, but only partially implemented, and Abadi's spokesman played down any prospect of immediate action.
Baghdad's concrete barriers were first put up during the 2003-2011 U.S. occupation as an insurgency began raging.
(Additional reporting by Said Hameed and Raheem Salman; Writing by Michael Georgy)