ISIS showed its resilience Wednesday with a counterattack that forced U.S.-backed Syrian rebels to abandon an offensive aimed at capturing a Syria-Iraq border town whose success would have effectively cut the so-called "caliphate" in two.
In another blow to the U.S. effort to train and equip "moderate" Syrian rebels, the surprise attack by ISIS inflicted a defeat on New Syrian Army effort to take the town of al-Boukamal, just across the border from the Iraqi town of al-Qaim. The New Syrian Army forces retreated and reportedly were regrouping in the desert.
Muzahem al Saloum, a spokesman for the New Syrian Army, told Reuters, "We have withdrawn to the outlying desert and the first stage of the campaign has ended."
"The news is not good," another rebel source told Reuters. "I can say our troops were trapped and suffered many casualties and several fighters were captured and even weapons were taken."
The Britain-based Syrian Observatory for Human Rights monitoring group also reported that the New Syrian Army had been driven back from al-Boukamal. The ISIS-linked Amaq news agency said ISIS fighters also drove the rebels from the nearby Hamdan air base while seizing 15 hostages and ammunition.
Al-Boukamal was considered the last remaining key supply and communications routes for the Islamic State of Iraq and Syria between its branches in Iraq and Syria.
Earlier Wednesday in a briefing from Baghdad to the Pentagon, Army Col. Chris Garver said that the New Syrian Army had been steadily advancing on al-Boukamal with the backing of U.S. airstrikes.
To the north in Syria in the ISIS-held town of Manbij, forces of the Syrian-Arab Coalition (SAC), another Syrian rebel faction backed by the U.S., seized the entrances to a major tunnel complex and also confiscated numerous documents, cell phones and hard drives, said Garver, a spokesman for Combined Joint Task Force-Operation Inherent Resolve.
However, ISIS defenders were "providing a tough fight to the SAC," using interlaced networks of earthen berms and improvised explosive devices, to blunt the effort to take Manbij, Garver said.
In Iraq, Garver said that a combination of Iraqi police and Sunni tribal forces from Anbar province had begun moving into Fallujah to restore order following the liberation last week of the city 40 miles west of Baghdad.
"It's going on right now. We're seeing that handover starting to take place" from the Iraqi Security Forces in control of Fallujah to the police and tribal forces, Garver said.
The resistance by ISIS fighters in Fallujah "was not as stiff as what we saw in Ramadi," Garver said, referring to the city west of Fallujah that was retaken late last year.
The effort to retake Fallujah forced thousands of residents to flee, resulting in overcrowded tent camps on the outskirts without shelter or water for many, according to the United Nations and humanitarian groups.
The U.S. military has not been tasked with providing relief for the Fallujah refugees and there were no plans to do so in the works, Garver said. "That's clearly outside CJTF's lane," he said.
"We haven't been asked to provide that type of support" and "we are not providing that support right now."
-- Richard Sisk can be reached at Richard.Sisk@Military.com.