QAIM, Iraq – U.S. troops battled insurgents holed up in houses and driving explosives-laden vehicles in a second town near the Syrian border Sunday, killing 28 in an expansion of their 2-day-old offensive chasing al-Qaida fighters along the Euphrates River valley, the military said. Al-Qaida in Iraq claimed to have taken two Marines captive during the fighting and threatened to kill them within 24 hours unless all female Sunni detainees are released from U.S. and Iraqi prisons in the country. The U.S. military said the claim appeared false. “There are no indications that the al-Qaida claims … are true,” said Multinational Force West, the command in the region. It said it was conducting checks “to verify that all Marines are accounted for.” Even as the fighting continued, political differences among Iraqi leaders deepened ahead of the crucial Oct. 15 national vote on a new constitution. Iraq’s Kurdish president, Jalal Talabani, called on the Shiite prime minister to step down over accusations he is monopolizing power in the government and ignoring his Kurdish coalition partners’ demands, a spokesman for Talabani’s Patriotic Union of Kurdistan said. AD Quality Auto 360p 720p 1080p Top articles1/5READ MOREThe top 10 theme park moments of 2019 The U.S. military says al-Qaida in Iraq, the country’s most fearsome insurgent group, has turned the area near the border into a “sanctuary” and a way station for foreign fighters entering from Syria. In Karabilah, Marines clashed with insurgents who opened fire from a building on Sunday in a firefight that killed eight militants, the military said. The move into Karabilah widened the sweep launched a day earlier by 1,000 Marines, soldiers and sailors, starting with nearby Sadah – a tiny village about eight miles from the Syrian border. Most of the militants appeared to have slipped out of Sadah before the force moved in, and hundreds of the village’s residents fled into Syria ahead of the assault. There was “virtually no opposition” in Sadah, the Marine commander in western Anbar province, Col. Stephen W. Davis, told The Associated Press. At least 28 militants were killed in fighting Sunday, Davis said, bringing the two-day toll among insurgents to 36. There have been no serious U.S. casualties in the operation, he said. 160Want local news?Sign up for the Localist and stay informed Something went wrong. Please try again.subscribeCongratulations! You’re all set!