BEIRUT (AP) — The U.S.-led coalition said Wednesday it is monitoring a convoy of IS militants that evacuated the Lebanon border headed toward eastern Syria under a controversial agreement brokered by Hezbollah and may strike at them.

Coalition spokesman Col. Ryan Dillon told The Associated Press the coalition has already struck a small bridge and punched a crater in a road to keep them from moving further east toward the border with Iraq.

"We are monitoring their location in real time," he said, adding that the coalition "will not rule out strikes against IS fighters being moved."

Syrian opposition activists said the convoy, which left the Lebanon-Syria border on Tuesday, is still in government-held territory in eastern Syria.

The IS militants were allowed to evacuate the area in buses following a Hezbollah-negotiated deal that allows them to go to IS-held territory near the Iraqi border.

Dillon said "we are not party to any agreements that were made by the Lebanese Hezbollah and ISIS or the (Syrian) regime." ISIS is another acronym for the Islamic State group.

He added that any strike will be in "accordance of the law of armed conflict and if we are able to do so and can discriminate and discern the difference between fighters and civilians."

His comments came hours after another U.S. official blasted the deal that led to the evacuation of hundreds of Islamic State fighters and civilians, saying the extremists should be killed on the battlefield.

The evacuation agreement, the first such publicized deal, had already angered many Iraqis who accused Syria and Lebanon's Hezbollah of dumping the militants on the Iraqi border rather than eradicating them.

The top U.S. envoy for the international coalition against IS, Brett McGurk, tweeted Wednesday that IS "terrorists should be killed on the battlefield, not bused across #Syria to the Iraqi border without #Iraq's consent." McGurk added that the anti-IS coalition will help ensure that "these terrorists can never" enter Iraq.

Lebanese troops launched an attack against IS on Aug. 18, while Syrian troops and Hezbollah fighters launched a simultaneous offensive from the Syrian side of the border. The militants agreed to a cease-fire over the weekend once they had been squeezed into a small area along the frontier.

Lebanon has defended the agreement, in which the militants are said to have revealed the location of the remains of nine Lebanese soldiers who had been captured in 2014.