When US sentries fatally shot three guards near an Iraqi manned checkpoint south of Baghdad, they thought they were targeting enemy fighters planting roadside bombs, the US commander in the region said.
The shootings, which are still under investigation, underscore a new dilemma facing US troops as former fighters join forces against extremists and Iraqis are increasingly forced to take up arms to protect themselves -- how does one distinguish them from the enemy?
The US military said US troops shot the three civilians on Thursday near a checkpoint manned by local members of a US-allied group helping provide security in the village of Abu Lukah, near Musayyib, a Shiite-dominated town 65km south of Baghdad.
Major General Rick Lynch, commander of the 3rd Infantry Division that controls territory south of the Iraqi capital, stressed the investigation was continuing but said initial results showed that US troops fired on the checkpoint after spotting what appeared to be enemy forces planting roadside bombs.
"We are not looking to see who made a mistake but rather see what we can learn from that particular event," Lynch said on Saturday during a whirlwind tour of patrol bases in the area.
Lynch said it's critical to "better coordinate between coalition forces, Iraqi security forces and concerned citizens," as he calls the vigilante-style groups that have sprouted across the country to fight extremists.
The comments reflect rising concerns about possible friendly fire killings that could threaten to undermine the US strategy of seeking alliances with local Sunni and Shiite leaders against insurgent factions to fill the vacuum left by a national police force that has been plagued by allegations of corruption and infiltration by militants.
Incidents of shooting of civilians at checkpoints has drawn allegations by many, in Iraq and beyond, that US troops and contractors are quick to fire and ask question later.
After the Abu Lukah shooting, the North of Hillah Awakening Council staged a three-day strike to register its anger over the loss of three of its members, but guards resumed their posts on Sunday.
"Such acts will create a gap between us and the Americans. We are trying to restore security in the area while the Americans are killing us," Nabil Saleh, 37, said as he stood with his AK-47 slung over his shoulder at his post in Abu Lukah.
Jabar Hamid, a 33-year-old Shiite from the village, said the US military had paid US$2,500 to each family of the three men killed.
"It is a tragedy and regrettable thing," he said.
In a bid to distinguish the recruits, the groups have been given vests with reflective stripes, similar to those worn by traffic police in many countries. Others wear brown T-shirts, with Iraqi hats similar to the national army's.
US Captain John Newman said the soldiers believe they can discern volunteers from the insurgents.
"We've given them their road guard vests," Newman said. "So, he'd better be wearing that vest if I see him carrying an AK-47."
Lynch said the US soldiers are not arming the groups because it is not necessary, the men already have weapons, primarily AK-47s that are legally permitted in Iraqi households.
"We are allowing the people of Iraq to secure their own areas and they are using their personal firearms to do that," he said.
Iraqi Prime Minister Nouri al-Maliki and other Shiite leaders have expressed concern over the US policy of sponsoring armed Sunnis, many of whom were likely former insurgents.
"Acceptance rules for these recruits should be within a legal framework so that we do not allow the emergence of new militias," the Shiite prime minister said on Friday.