Sunni militants have seized an Iraqi crossing on the border with Syria after a daylong battle in which they killed some 30 Iraqi troops, security officials said Saturday.
The capture of the Qaim border crossing deals a further blow to Prime Minister Nouri al-Maliki's government, which has struggled to push back against Islamic extremists and allied militants who have seized large swaths of the country, including the second largest city Mosul, and who have vowed to march on Baghdad.
Police and army officials said the Islamic State of Iraq and the Levant and allied militants seized the crossing near the border town of Qaim, about 320 kilometres (200 miles) west of Baghdad, after battling Iraqi troops all day Friday.
The officials, who spoke on condition of anonymity because they were not authorized to talk to media, said people were now crossing back and forth freely.
Sunni militants have carved out a large fiefdom astride the Iraqi-Syrian border and have long travelled back and forth with ease, but the control of crossings allows them to more easily move weapons and heavy equipment to different battlefields.
The fall of the border crossing came as al-Maliki faces mounting pressure to form an inclusive government or step aside, with both a top Shiite cleric and the White House strongly hinting he is in part to blame for the worst crisis since U.S. troops withdrew from the country at the end of 2011.
Grand Ayatollah Ali al-Sistani, the most respected voice for Iraq's Shiite majority, on Friday joined calls for al-Maliki to reach out to the Kurdish and Sunni minorities a day after President Barack Obama challenged him to create a leadership representative of all Iraqis.
Al-Sistani normally stays above the political fray, and his comments, delivered through a representative, could ultimately seal al-Maliki's fate.
Calling for a dialogue between the political coalitions that won seats in the April 30 parliamentary election, al-Sistani said it was imperative that they form "an effective government that enjoys broad national support, avoids past mistakes and opens new horizons toward a better future for all Iraqis."
Al-Sistani is deeply revered by Iraq's majority Shiites, and his critical words could force al-Maliki, who emerged from relative obscurity in 2006 to lead the country, to step down.
On Thursday, Obama stopped short of calling for al-Maliki to resign, but his carefully worded comments did all but that. "Only leaders that can govern with an inclusive agenda are going to be able to truly bring the Iraqi people together and help them through this crisis," Obama said.
The Iranian-born al-Sistani, believed to be 86, lives in the Shiite holy city of Najaf, south of Baghdad, where he rarely ventures out of his modest house and does not give media interviews. His call to arms last week prompted thousands of Shiites to volunteer to fight against the Sunni militants.
His call to defend the country has given the fight against the Sunni insurgents the feel of a religious war, but his office in Najaf dismissed that charge, saying the top cleric was addressing all Iraqis.
But on Friday hundreds of black-clad Shiite militants, members of the newly formed "Peace Brigades," marched in the Shiite holy city of Najaf, heeding a call to defend holy sites by Shiite cleric Muqtada al-Sadr, who once led a powerful militia that battled U.S. troops and was blamed for attacks on Sunni civilians during the height of the country's sectarian bloodletting in 2006 and 2007.
Al-Maliki's State of Law bloc won the most seats in the April vote, but his hopes to retain his job are in doubt, with rivals challenging him from within the broader Shiite alliance. In order to govern, his bloc must first form a majority coalition in the new 328-seat legislature, which must meet by June 30.
If al-Maliki were to relinquish his post now, according to the constitution the president, Jalal Talabani, a Kurd, would assume the job until a new prime minister is elected. But the ailing Talabani has been in Germany for treatment since 2012, so his deputy, Khudeir al-Khuzaie, a Shiite, would step in for him.
Shiite politicians familiar with the secretive efforts to remove al-Maliki said two names mentioned as replacements are former vice-president Adel Abdul-Mahdi, a Shiite and French-educated economist, and Ayad Allawi, a secular Shiite who served as Iraq's first prime minister after Saddam Hussein's ouster. Others include Ahmad Chalabi, a one-time Washington favourite to lead Iraq, and Bayan Jabr, another Shiite who served as finance and interior minister under al-Maliki.
Nearly three years after he heralded the end of America's war in Iraq, Obama announced Thursday he was deploying up to 300 military advisers to help quell the insurgency. They join some 275 troops in and around Iraq to provide security and support for the U.S. Embassy and other American interests.
But Obama has been adamant that U.S. troops would not be returning to combat.
He has also held off approving the airstrikes sought by the Iraqi government, though he says he could still approve "targeted and precise" strikes if the situation required it and if U.S. intelligence gathering identified potential targets.
Manned and unmanned U.S. aircraft are now flying over Iraq 24 hours a day on intelligence missions, U.S. officials say.