Story highlights U.S. tried to kill ISIS leaders with airstrike on convoy near Mosul, official says

Official can't confirm top Abu Bakr al-Baghdadi was in convoy

Airstrike kills 15, hurts 31 in Al-Qaim, an ISIS stronghold in Iraq, resident says

Iraq welcomes news that U.S. will send another 1,500 troops

U.S. warplanes attacked a convoy near Mosul in Iraq this weekend in an attempt to kill ISIS leaders, said a spokesman for U.S. Central Command.

Col. Patrick Ryder, in a statement Saturday, said he could not confirm that top ISIS leader Abu Bakr al-Baghdadi was in the convoy.

Ryder issued that information in response to news reports indicating the ISIS leader may have died or been injured.

"I can confirm that coalition aircraft did conduct a series of airstrikes yesterday evening in Iraq against what was assessed to be a gathering of ISIL leaders near Mosul, destroying a vehicle convoy consisting of 10 ISIL armed trucks," Ryder said, using another acronym for ISIS.

Mosul, Iraq's second-largest city, is crucial to ISIS. Besides having material resources, such as Iraq's largest hydroelectric dam, Mosul is the site of one of ISIS's greatest battlefield victories

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In June, the Sunni Muslim extremist group overran the city , causing soldiers and police officers to drop their weapons and flee, according to numerous witnesses. ISIS announced plans to establish a caliphate, or Islamic state, in Mosul after the takeover.

In another airstrike against an ISIS stronghold, at least 15 people were killed and 31 were wounded when planes hit the town of Al-Qaim, in Anbar province, on the border with Syria, a witness said Saturday.

The town is 286 kilometers (178 miles) from Mosul.

The strike hit a market near an ISIS checkpoint in the town, according to the resident who cannot be named for safety reasons. The resident, who went to a local hospital after the strike and saw the wounded, did not know whether there were any ISIS casualties from the strike.

Al-Qaim became a stronghold for ISIS, the Sunni Muslim extremist group, after militants took control in June.

U.S. officials in Washington declined comment Saturday when CNN asked whether coalition or U.S. forces carried out the airstrike.

Car bombs in Baghdad

Elsewhere in Iraq, car bombs hit four areas of Baghdad, including a busy commercial street, killing at least 21 people, police officials said.

No public claims of responsibility were immediately made. But the attacks come after years of sectarian violence in the country, including some recent Baghdad car bombings that were claimed by ISIS.

One of Saturday's bombs struck the busy al Sinaa commercial street in central Baghdad, killing at least 10 people and injuring 27 others, Baghdad police officials said.

The other bombs hit predominantly Shiite Muslim neighborhoods.

One exploded near an outdoor market in eastern Baghdad's Sadr City, killing one and injuring seven others, police said.

Two other bombs exploded outside a fuel station in southwestern Baghdad's al-Amil neighborhood, killing at least seven people and injuring 22 others, according to police.

And a car bomb struck near a restaurant in eastern Baghdad's al-Ameen neighborhood, killing three people and injuring 15 others.

1,500 more troops to Iraq

On Saturday, Iraq welcomed the U.S.-led coalition decision to provide more support in training and arming the Iraqi armed forces to help fight ISIS, but added "this step is a little late."

The comment comes a day after the Obama administration announced the deployment of 1,500 more soldiers to Iraq to train Iraqi and Kurdish forces to confront ISIS.

Iraq has allocated four to five training centers and U.S.-led coalition members have started sending trainers, Prime Minister Haider al-Abadi's office said in a statement.

Meanwhile, al-Abadi's office added that the arming of Iraq tribes is done exclusively through the Iraqi government, with the supervision of its armed forces.