Iraqi officials have said that some of the attackers that carried out a series of bombings in Baghdad that left hundreds of people dead in recent months had disguised themselves as security personnel to pass checkpoints in the capital.
Sabah al-Khaiyat, a tailor in Baghdad, said he had turned away a number of potential clients because they were suspicious or could not provide proper documentation.
"One day a man came to me asking me to sew a military uniform similar to the ones worn by the American army," al-Khaiyat said.
"Most uniforms, police or military, are easy to imitate, so they tell the security forces very little about an individual trying to gain access to an area"
Major Sylvester O. Wegwu,
US military adviser
But he said that he decided not to take his order because he looked "suspicious to me".
There are dozens of styles of uniforms among the various branches of the police and military forces in Iraq, each with their own insignia and design requirements.
"Most uniforms, police or military, are easy to imitate, so they tell the security forces very little about an individual trying to gain access to an area," Major Sylvester O. Wegwu, a US military adviser working at Baghdad police college, said.
Despite promises from the interior ministry that it would provide uniforms for all police officers, many have been forced to buy their own.
The interior and defence ministries have been unable to meet the demand for uniforms, in part because only one factory in southern Iraq manufactures most of them.
Bombers in Iraq have routinely disguised themselves in uniforms to bypass security checks.
The problem was so prevalent in 2006 that the US military redesigned Iraqi federal police uniforms after the old one was copied by anti-government fighters, death squads and common criminals.
A US military adviser said Iraqi forces had been told not to focus on a person's uniform but rather on any suspicious behaviour when watching out for possible attackers.