Fighters from the largely Sunni Muslim militia in the Islamic State of Iraq and the Levant (ISIS) moved on to take more territory in Iraq's western province of Anbar on Sunday.

Iraqi military and police officials said militants overran the al-Waleed border crossing with Syria as officials pulled out when gunmen started firing. On Saturday, ISIS fighters had seized another frontier crossing with Syria near the town of Qaim.

There were also reports that the Turaibil border crossing with Jordan had been captured by ISIS militants. On Saturday, fighters had captured Rutba, a key town on the last part of a highway from Iraq towards Jordan.

The advance followed the capture since Friday of the towns of Qaim, Rawah, Anah and Rutba. All are in the Sunni Anbar province where ISIS militants have controlled the city of Fallujah and parts of the provincial capital Ramadi since January.

The capture of Rawah on the Euphrates river and the nearby town of Anah appeared to be part of a march toward a key dam near the city of Haditha. If destroyed, it would damage the country's electrical grid and cause major flooding. Iraqi military officials said more than 2,000 troops had been sent to the site of the dam to protect it.

Speaking in an interview broadcast on CBS television's "Face the Nation" on Sunday about Iraq, US President Barack Obama said: "We're going to have to be vigilant generally. Right now the problem with ISIS is the fact that they're destabilizing the country," he said. "That could spill over into some of our allies like Jordan," Obama added. "They are engaged in wars in Syria where, in that vacuum that's been created, they could amass more arms, more resources."

US Secretary of State John Kerry made an unexpected visit to Egypt on Sunday where he said, "terrorists are the greatest threat to the Middle East."

Iran leader comment

Iran's supreme leader, Ayatollah Ali Khamenei said on Sunday he was opposed to any US intervention in Iraq. Khamenei said: "We strongly oppose the intervention of the US and others in the domestic affairs of Iraq."

"The main dispute in Iraq is between those who want Iraq to join the US camp and those who seek an independent Iraq," said Khamenei. "The US aims to bring its own blind followers to power."

The Ayatollah's comments are the clearest indication so far of opposition to the US plan to send 300 military advisers to Iraq. They also indicate the difficulties of any cooperation between Washington and Tehran in defending their mutual ally in the government of Shiite Prime Minister Nuri al-Maliki.

jm/pfd (AP, Reuters, AFP)