Iran's foreign minister said in Baghdad Sunday Tehran is working to help combat jihadist-led militants but does not have soldiers in Iraq, amid a renewed push for a key oil refinery.
The United States, whose warplanes have launched more than 90 air strikes against Islamic State (IS) jihadists in Iraq since August 8, has said operations against the group in Syria may also be necessary.
Washington has also ramped up its rhetoric over the grisly IS beheading in Syria of abducted American journalist James Foley, calling it "a terrorist attack against our country".
Iraq is struggling to regain ground lost to a major IS-led militant offensive which began in June and quickly overran large areas of five provinces, sweeping security forces aside.
"We are cooperating and working... with the Iraqi government and with the Kurdish government in order to repel this very serious, atrocious group," Iranian Foreign Minister Mohammad Javad Zarif said of IS.
"But we do not believe that they need the presence of Iranian soldiers in order to do this task," he said at a joint news conference with his Iraqi counterpart Hoshyar Zebari.
There have been reports of Iranian forces fighting in Iraq, and despite Zarif's denial, evidence including an Iranian pilot state media said was killed fighting in Iraq and the presence of several Iranian Su-25 warplanes points to a more direct military role by Iraq's Shiite neighbour to the east.
Zarif also called for an international effort against IS.
It is "committing acts of horrendous genocide and crimes against humanity" and "needs to be tackled by the international community and by every country in the region", he said.
As Zarif visited Baghdad, security forces backed by air support battled a renewed militant push towards the Baiji refinery, which once accounted for some 50 percent of Iraq's supplies of refined petroleum products, and has been targeted in the past.
The latest unrest came as the death toll from a string of attacks in and north of Baghdad on Saturday rose to at least 37, a health official said.
- Call to close ranks -
Officials have been trying to calm tensions caused by an attack two days ago on a Sunni mosque in Diyala province.
Gunmen sprayed worshippers with machinegun fire, killing at least 70 people and wounding 20, officials said.
Dubbed by rights group Amnesty International a "massacre" that Iraqi authorities "must properly investigate", the attack threatens to increase anger among the Sunni Muslim minority with the Shiite-led government at a time when the anti-IS drive depends on their cooperation.
Parliament speaker Salim al-Juburi, a Sunni, called on Saturday for political unity and said "the main aim (of the mosque attack) is to foil all the efforts that have been made to form a government".
"All the political entities condemned the crime, all of them expressed their anger about what happened," he said in televised remarks.
Prime minister-designate Haidar al-Abadi, a Shiite, urged "citizens to close ranks to deny the opportunity to the enemies of Iraq who are trying to provoke strife".
Army and police officers said the assault on the Musab bin Omair Mosque in Diyala came after Shiite militiamen were killed in clashes, while other sources said it followed a roadside bombing near a militia patrol.
Although some officers blamed IS for the attack, most accounts, including one from an eyewitness, pointed to Shiite militiamen.
The government turned to militias to bolster its flagging forces during the IS-led offensive, but in doing so it has encouraged a resurgence of groups involved in brutal sectarian killings in past years.
- Danger of 'massacre' -
The United Nations, meanwhile, warned that the Shiite Turkmen-majority northern Iraqi town of Amerli is under threat of a "massacre" by jihadists who have besieged it for more than two months.
"The situation of the people in Amerli is desperate and demands immediate action to prevent the possible massacre of its citizens," UN Iraq envoy Nickolay Mladenov said in a statement.
Abadi and Iraq's top Shiite cleric, Grand Ayatollah Ali al-Sistani, both also called for efforts to help Amerli.
The killing by IS of American journalist Foley has stoked Western fears that territory seized by the militants in Syria and Iraq could become a launchpad for a new round of global terror attacks.
The 40-year-old freelancer was kidnapped in northern Syria in November 2012.
In a video released online, a masked black-clad militant said Foley was killed in revenge for US air strikes against IS.
The supposed executioner, speaking with a south London accent, paraded a second American reporter, Steven Sotloff, in front of the camera and said he would also die if the air raids continued.
Source: AFP