BEIRUT — U.S. forces ferried by helicopter Sunday crossed five miles into Syria from Iraq and launched a commando raid that left at least eight people dead, Syrian news outlets and sources reported.
Syria has long been a conduit for foreign fighters attempting to slip into Iraq to attack U.S. troops. American officials say that military action in Iraq has reduced the number of those fighters. And tense relations between Damascus and the Iraqi government have improved enough that this month Syria sent an ambassador to Baghdad for the first time since the early 1980s.
But U.S. officials complain that militants still are able to operate openly in Syria, and that the Damascus government needs to do more to rein them in. They accuse fighters who filtered across the Syrian border of fomenting trouble recently in the northern city of Mosul, and of an attack in May that killed 11 Iraqi policemen.
Details of the attack Sunday were sketchy. A military officer in Iraq confirmed that U.S. forces had conducted a raid into Syria, but declined to provide more information. In Washington, several military representatives who were asked about the operation did not deny that a raid had taken place. Although they would not confirm the attack, they used language typically employed after raids conducted by secretive special operations forces.
In the waning days of the Bush administration, the U.S. has shown a greater willingness to launch cross-border clandestine operations in another military theater, Pakistan, to protect U.S. troops in neighboring Afghanistan or to capture or kill Islamic militants.
The official Syrian Arab News Agency said U.S. military helicopters attacked the Sukkariyeh Farm near the town of Abu Kamal. The area is about 60 miles southeast of Dayr az Zawr, which is considered a haven for Sunni Arab militants that infiltrate Iraq and is near the site of a Sept. 6, 2007, Israeli airstrike on what U.S. officials have alleged was a plutonium plant built with the assistance of North Korea.
The news agency said four helicopters crossed into Syrian airspace about 4:45 p.m. local time and fired on people who appeared to be laborers at their jobs on the second day of the Syrian workweek. It said a man named Daoud Mohammed Abdullah, his wife and four of his sons were killed. The two other victims were not immediately identified.
"All victims were civilians," Syria's Dunya private television said.
People told the news media that they saw two helicopters land and eight U.S. soldiers get off. Syrian state television said the troops stormed a building.
There have been few reports of the U.S. military firing across the Syrian border since the U.S.-led invasion of Iraq in 2003. But Sunday's attack, if confirmed, would appear to be the first time that U.S. troops have launched an attack inside Syria.
Damascus and Washington have taken steps recently toward easing their strained relations.
Last month Syrian Foreign Minister Walid Moallem met briefly with Secretary of State Condoleezza Rice.
But on Sunday, the Syrian Foreign Ministry summoned the top U.S. and Iraqi diplomats in Damascus and complained of "dangerous aggression," the news agency said. It demanded that Iraq immediately begin an investigation of the attack and that it prevent foreign forces from using Iraqi territory to launch strikes.
It was unclear how the raid would affect U.S.-Iraqi negotiations over an agreement to extend the American military presence in Iraq. Syria and Iran have opposed the agreement, in part out of fear that U.S. forces would use Iraq as a base to strike at them.
U.S. officials have asked Arab leaders to pressure Syria to tighten its visa restrictions on "military-aged males," in an effort to prevent would-be militants from flying to Damascus and then making their way to the Iraqi border.
Military units in Iraq have focused on shutting down the "rat lines" that shuttled militants from the Syrian border to the city of Ramadi and on to Baghdad.
This month Gen. David H. Petraeus, the former top commander in Iraq, said those efforts had helped cut the number of foreign fighters crossing the Syrian border from about 100 to 20 a month. But he made it clear that more needed to be done.
In recent weeks, military commanders have increased their focus on the threat from militants in Syria who are blamed for cross-border attacks in western Iraq and for fueling violence in Mosul.
"The Iraqi security forces and the Iraqi intelligence forces feel that Al Qaeda operatives and others operate [and] live pretty openly on the Syrian side," Marine Maj. Gen. John Kelly, commander of U.S. troops in western Iraq, said at a briefing for reporters last week. "And periodically we know that they try to come across."
Kelly said that after the May attack on the police officers, in which some were beheaded, Iraqi security forces have tried harder to secure the border.
Kelly said his Marine forces were training Iraqi border guards. But he also said U.S. and Iraqi forces were building a large sand berm and system of ditches to keep vehicles from crossing the border.
Times staff writers Ned Parker in Baghdad and Tony Perry in San Diego, and special correspondent Ziad Haidar in London contributed to this report.