Story highlights U.S. military releases video of airstrike in Syria, says it hit an ISIS compound

Airstrikes hit near Ayn al-Arab, the site of fighting between ISIS and Syrian Kurdish forces

London-based monitoring group says other airstrikes kill six civilians near al-Hasakah

Al-Qaeda group in Syria denounces Muslim countries participating in airstrikes

U.S. and allied warplanes hit sites near the northern Syrian city of Ayn al-Arab, the scene of fighting between ISIS and Kurdish forces in recent days, U.S. Central Command confirmed Saturday.

A video released by the U.S. military shows a missile hitting a building. U.S. Central Command said it was taken from an F-15E fighter jet that struck an ISIS compound near Kobani, the Kurdish name for Ayn al-Arab.

In other airstrikes near Ayn al-Arab, coalition forces hit two armed vehicles at a border crossing with Turkey, the military said.

Syrian Kurdish fighters in Alishar, a village a few kilometers from Ayn al-Arab, said the airstrike hit an unofficial border crossing near the village.

The strikes are believed to be the first known coalition attacks near the border with Turkey. That country is not participating in the airstrikes and has repeatedly pressed for an international buffer zone separating the combat in Syria from the Turkish border.

Photos: U.S., Arab nations attack ISIS in Syria Photos: U.S., Arab nations attack ISIS in Syria U.S., Arab nations attack ISIS in Syria – In this photo released by the U.S. Air Force, fighter jets fly over northern Iraq as part of coalition airstrikes in Syria on Tuesday, September 23. The United States and several Arab nations have started bombing ISIS targets in Syria to take out the militant group's ability to command, train and resupply its fighters. Hide Caption 1 of 13 Photos: U.S., Arab nations attack ISIS in Syria U.S., Arab nations attack ISIS in Syria – A U.S. Navy jet is refueled in flight after airstrike missions in Syria on September 23. In addition to bombing ISIS, the United States has also taken action -- on its own -- against another terrorist organization, the Khorasan Group. U.S. President Barack Obama described Khorasan members as "seasoned al Qaeda operatives in Syria." Hide Caption 2 of 13 Photos: U.S., Arab nations attack ISIS in Syria U.S., Arab nations attack ISIS in Syria – This photo, released by activists in Idlib, Syria, on September 23, shows what they say is the aftermath of U.S. airstrikes against ISIS. Hide Caption 3 of 13 Photos: U.S., Arab nations attack ISIS in Syria U.S., Arab nations attack ISIS in Syria – Another aftermath image from the Idlib activists. Hide Caption 4 of 13 Photos: U.S., Arab nations attack ISIS in Syria U.S., Arab nations attack ISIS in Syria – Obama, speaking at the White House on September 23, addresses the ISIS airstrikes. "The strength of this coalition makes it clear to the world that this is not America's fight alone," Obama said. Hide Caption 5 of 13 Photos: U.S., Arab nations attack ISIS in Syria U.S., Arab nations attack ISIS in Syria – The USS Philippine Sea, a guided-missile cruiser with the U.S. Navy, launches a Tomahawk cruise missile from the Persian Gulf during an attack on ISIS positions on September 23. The U.S. Navy released this photo and several others following the airstrikes. Hide Caption 6 of 13 Photos: U.S., Arab nations attack ISIS in Syria U.S., Arab nations attack ISIS in Syria – U.S. sailors stand on the bridge of the USS Philippine Sea while Tomahawk cruise missiles are launched toward targets in Syria on September 23. Hide Caption 7 of 13 Photos: U.S., Arab nations attack ISIS in Syria U.S., Arab nations attack ISIS in Syria – The USS Arleigh Burke, a guided-missile destroyer with the U.S. Navy, launches Tomahawk missiles in the Persian Gulf on September 23. Hide Caption 8 of 13 Photos: U.S., Arab nations attack ISIS in Syria U.S., Arab nations attack ISIS in Syria – An F/A-18C Hornet prepares to take off from the flight deck of the USS George H.W. Bush, a U.S. Navy aircraft carrier in the Persian Gulf, before conducting strike missions against ISIS targets on September 23. Hide Caption 9 of 13 Photos: U.S., Arab nations attack ISIS in Syria U.S., Arab nations attack ISIS in Syria – Tomahawk missiles fired by the USS Philippine Sea fly in the air above the Persian Gulf on September 23. Hide Caption 10 of 13 Photos: U.S., Arab nations attack ISIS in Syria U.S., Arab nations attack ISIS in Syria – Two more U.S. fighter jets prepare to take off from the USS George H.W. Bush and conduct airstrikes against ISIS targets in Syria. Hide Caption 11 of 13 Photos: U.S., Arab nations attack ISIS in Syria U.S., Arab nations attack ISIS in Syria – This before-and-after image, provided by the U.S. Department of Defense, shows what is purported to be an ISIS command center that was targeted by airstrikes in Raqqa, Syria. Hide Caption 12 of 13 Photos: U.S., Arab nations attack ISIS in Syria U.S., Arab nations attack ISIS in Syria – The Defense Department also released this before-and-after image of a purported ISIS finance center in Raqqa. Hide Caption 13 of 13

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A London-based monitoring group also claimed Saturday that other airstrikes may have also resulted in the deaths of six civilians near the Syrian city of al-Hasakah.

CNN could not independently confirm the report from the London-based Syrian Observatory for Human Rights.

U.S. Central Command did say Saturday that airstrikes hit an ISIS vehicle and several buildings that were part of an ISIS garrison near al-Hasakah.

A purported video statement posted online Saturday by Al-Nusra Front, the al Qaeda franchise in Syria, condemns the U.S.-led coalition airstrikes. A man identified as Abu Firas al-Souri, spokesman for the group, denounced the participation of Muslim countries in the coalition.

In addition to U.S. Air Force and Navy aircraft, warplanes from Saudi Arabia, Jordan and the UAE participated in strikes in Syria, which also targeted ISIS forces in several other locations, Central Command said.

A Kurdish fighter in the region and the Syrian Observatory for Human Rights had earlier reported airstrikes in the vicinity of the village of Alishar, west of Ayn al-Arab.

Coalition airstrikes also destroyed ISIS vehicles and a fighting position near Erbil, Iraq, Central Command said.

JUST WATCHED USS George H.W. Bush targets ISIS Replay More Videos ... MUST WATCH USS George H.W. Bush targets ISIS 01:59

Kurdish forces have been battling ISIS for days to prevent the fall of Ayn al-Arab. It is the last Kurdish-held city in that region of northwest Syria following a swift ISIS assault that sent some 200,000 people running for their lives to Turkey.

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At least four mortar rounds believed fired by ISIS forces have landed in Kobani, according to to Alan Minbic, a Syrian Kurdish soldier who was fighting in an area between Ayn al-Arab and Aidek.

JUST WATCHED USS George H.W. Bush targets ISIS Replay More Videos ... MUST WATCH USS George H.W. Bush targets ISIS 01:59

A CNN crew witnessed the Kurdish fighters using artillery and heavy machine-gun fire to drive the ISIS fighters back from the ridge line they were occupying.

Denmark and Belgium also signed up on Friday, adding to a list of more than 50 European, Asian and Arab countries that have joined the fight, according to U.S. officials.

U.S. forces continue to hunt targets in Iraq and Syria, with aircraft taking off from the USS George H.W. Bush as often as every 55 seconds, according to CNN's Becky Anderson, who is aboard the aircraft carrier in the Persian Gulf.

The United States launched airstrikes against ISIS in August in an effort to stem the group's breathtaking advance across Iraq. The group, which calls itself the Islamic State, routed Iraqi forces and took over vast swaths of the country. Some analysts warned Baghdad was at risk of falling to the well-armed, organized and funded extremist group without Western involvement.

While the most dramatic advances have been halted, Western leaders have warned of a long fight against ISIS, saying it could take years before the group is fully dislodged.