By Ed Payne and Laura Smith-Spark
(CNN) -- Iraq's military claimed Wednesday to have driven back militants who stormed the country's main oil refinery in the town of Baiji, the latest front in the battle for control of swaths of Iraq.
Iraqi forces killed 40 militants from the Islamic State in Iraq and Syria, or ISIS, said Iraqi military spokesman Gen. Qasem Atta, in a televised news conference. Baiji is 225 kilometers (140 miles) north of Baghdad, the capital.
"The situation in Tal Afar, Samarra, and Baiji is under control," Atta said.
He claimed that Iraq's military were "defeating ISIS in the Baiji area" and that "most of the areas" around the northwestern city of Tal Afar were liberated.
Tal Afar fell to the Sunni Muslim militants on Sunday, according to Iraq's military. Many Tal Afar residents, including ethnic minority Shiite Turkmen, fled the fighting north toward Iraq's Kurdish region.
On Tuesday, ISIS militants battled Iraqi security forces for control of Baquba, only 60 kilometers (37 miles) from Baghdad.
The fighters have "made a great advance on Baquba" and are pushing very hard to take it, officials said Tuesday. But the city has not fallen.
Holding on to cities so close to the capital, where nerves are fraying, may prove crucial to the Shia-dominated government of Iraqi Prime Minister Nuri al-Maliki.
What is happening in Iraq is increasingly taking on the urgency of an international crisis.
On Wednesday, U.S. President Barack Obama will huddle with congressional leaders. The topic of whether the United States should intervene -- and how -- is bound to come up.
The administration faces some tough choices.
Obama has ruled out ground troops. Airstrikes remain under consideration.
Turkish citizens kidnapped
Iraq's neighbor, Turkey, has seen its citizens caught up directly in the conflict.
A Turkish official told CNN on Wednesday that the country is aware "some construction workers in Kirkuk may have been kidnapped. We are following developments." Kirkuk is one of the provinces that has seen heavy fighting.
The latest reported incident follows the abduction of 48 Turkish citizens last week from the Turkish Consulate in Mosul, Iraq's second-largest city. It fell to ISIS militants just over a week ago after Iraqi forces collapsed.
The Turkish Foreign Ministry said Tuesday that all efforts continue toward the safe return to Turkey of the consulate staff and 31 other Turkish citizen held in Mosul's Geyara district.
Meanwhile, families -- mostly Shiite -- are leaving Baquba and other Iraqi cities in droves. They carry with them whatever possessions they can carry, even livestock.
Over the past week or so, ISIS militants have pressed forward, gobbling up large chunks of territory.
They have racked up several significant victories, including Tal Afar, Mosul and two villages in Diyala province.
The ISIS militants are Sunni Muslims and claim to have killed at least 1,700 Shiites since launching their offensive. Hundreds of thousands have fled, prompting fears of a humanitarian crisis.
Iraq's Cabinet said Tuesday it would give more than $850,000 in aid to help those displaced in Nineveh, Salaheddin and Diyala provinces.
The Obama administration appears to have some confidence that the insurgents will fail to take the capital.
A senior intelligence official drew a contrast between Iraqi Security Forces defending Baghdad and other Iraqi soldiers who melted away in the face of ISIS fighters across northern Iraq earlier this month.
"ISF elements protecting Baghdad are assessed to be more loyal to the regime and are composed of mostly Shia who are more likely to resist," the official said. "These factors, plus the fact that they are defending the capital, should motivate the ISF elements in Baghdad to put up a better fight."
Al-Maliki fired four top military officers that "deserted and did not fulfill their professional and national duty," according to a statement read Tuesday on state TV.
Among them were the operations command chief for Nineveh province -- of which Mosul is the capital -- and two of his officers, the statement said. Another commander will be tried in a military court in absentia for fleeing the battlefield to an unknown place.
The Iran variable
President Hassan Rouhani said on Wednesday that Iran will spare no effort to protect holy Shiite shrines in neighboring Iraq from "killers and terrorists," Iran's state-run Islamic Republic News Agency reported.
A senior security official in Baghdad told CNN last week that Iran had sent about 500 Revolutionary Guard troops to help fight the ISIS militants.
Rouhani denied the report over the weekend but said he would be open to helping if asked, though with strategic guidance rather than troops. Iran is often accused of using proxies to hold sway in the region but has never militarily intervened in any sovereign country.
Iran is closely allied with the Shia-led government of Iraq.
The United States and Iran held "very brief discussions" in Vienna, Austria, about Iraq and the threat posed by ISIS on Monday.
Forces on standby
Still, leaving nothing to chance, the Pentagon is moving more firepower and manpower into the region.
Already at the U.S. Embassy in Baghdad, dozens of Marines and Army troops have moved in to beef up security. Another 100 personnel are in the region to provide support if needed, the Pentagon said.
The aircraft carrier George H.W. Bush and five other warships are now in the Persian Gulf. More than 500 Marines and dozens of helicopters are on standby.
Speaking at a CNN town hall meeting on Tuesday, Hillary Clinton, former secretary of state and a potential 2016 presidential candidate, said the Iraqi government made a "mistake" by failing to forge an agreement with the United States to keep American troops in Iraq after the war.
The United States wanted American soldiers to be immune from prosecution. The Iraqi government resisted.
"It's imperative that the government of Iraq, currently led by Maliki, be much more inclusive, much more willing to share power, involve all the different segments of Iraq," she said.
"And I believe strongly that if Maliki is not the kind of leader who can do that, then the Iraqi people need to think seriously about the kind of leader they need to try to unite Iraqis against what is a terrible, imminent threat from these most extreme terrorists."
CNN's Nic Robertson reported from Baghdad, Ed Payne and Mohammed Tawfeeq reported in Atlanta and Laura Smith-Spark wrote in London. CNN's Sara Mazloumsaki, Jim Sciutto, Barbara Starr, Jim Acosta, Ted Barrett, Lisa Desjardins, Dana Ford, Ali Younes, Salma Abdelaziz, Raja Razek and Gul Tuysuz contributed to this report.
™ & © 2014 Cable News Network, Inc., a Time Warner Company. All rights reserved.