BAGHDAD - Iraq on Sunday pressed a counter-offensive against militants who have seized a swathe of the country, as former UN mediator Lakhdar Brahimi blamed the sweeping unrest on world neglect of the Syrian conflict.
As the United States responded to the crisis by deploying an aircraft carrier in the Gulf, Iran warned against foreign military intervention in its Shiite neighbour.
The militants, spearheaded by the powerful jihadist Islamic State of Iraq and the Levant (ISIL), have overrun all of one province and chunks of three more since they launched their offensive late last Monday.
Security forces have generally performed poorly, with some abandoning their vehicles and positions and discarding their uniforms, though they seem to have begun to recover from the initial onslaught and have started to regain ground.
Iraqi commanders have said security forces were now starting to push the militants back, and that soldiers had recaptured two towns north of Baghdad.
They will be joined by a flood of volunteers, urged on by a call to arms from top Shiite cleric Grand Ayatollah Ali al-Sistani.
Recruitment centre hit by shells
A recruitment centre for such volunteers at the town of Khales in central Iraq came under mortar attack on Sunday, leaving six people dead, including three Iraqi soldiers, police and a doctor said.
US President Barack Obama said he was "looking at all the options" to halt the offensive that has brought the militants within 50 miles (80 kilometres) of Baghdad's city limits, but ruled out any return of US combat troops.
Pentagon spokesman Rear Admiral John Kirby said Defence Secretary Chuck Hagel had ordered aircraft carrier USS George H.W. Bush into the Gulf in response to the crisis.
Obama has been under mounting fire from his Republican opponents over the swift collapse of Iraq's security forces, which Washington spent billions of dollars training and equipping before pulling out its own troops in 2011.
Iran warned on Sunday that "any foreign military intervention in Iraq" would only complicate the crisis.
"Iraq has the capacity and necessary preparations for the fight against terrorism and extremism," foreign ministry spokesman Marzieh Afkham was quoted as saying by the ISNA news agency.