AN Australian security contractor has been seriously wounded in a bomb blast in Iraq.

The 34-year-old Queensland man was injured when a roadside bomb exploded early on August 3, about 45km northeast of Baghdad, the Department of Foreign Affairs and Trade (DFAT) said.

"He's been quite badly injured in a roadside blast," Mr Downer said on Sky News.

The man's name is yet to be released.

The Department of Foreign Affairs said earlier today the 34-year-old man had been evacuated from Iraq after being injured in the roadside blast about 45km north-east of Baghdad on August 3.

"His situation is very serious," Mr Downer said.

"Two other people were killed at the same time, he's been very badly burnt.

"He comes originally from Melbourne, has been living in Townsville and he's been working for a security contractor in Iraq."

Two Iraqi citizens were killed in the same blast, a DFAT spokesman said.

"Consular officials in Australia are providing assistance to the man's family and embassy officials are working closely with the man's employer," the spokesman said.

The injured man had been evacuated from Iraq for medical treatment, the DFAT spokesman said.

The man's condition was still listed as serious, he said.

The department would not yet say which company the man was working for or where he was being treated for his injuries.

It was unclear how many Australians were working in Iraq as private security guards as most did not register with the Australian embassy there, a spokeswoman said.

But other counts have estimated that there are more than 20,000 - and possibly up to 30,000 - currently employed there, reportedly making private contractors the second largest security force in Iraq, behind the US deployment.

The contractors are mostly former military personnel, working for dozens of companies operating in Iraq, who are rewarded with lucrative contracts for the heightened danger they face there.

Attacks against them are common. One count said more than 340 had been killed and many more injured, but precise figures were difficult to ascertain.

In June, Wayne Schultz, another Queenslander working as a contractor in Iraq, was killed in a roadside bomb attack north of Baghdad.
- with AAP