Heavy fighting reported as US-backed forces attack last ISIS stronghold in Syria

Heavy fighting erupted Sunday as US-backed forces attacked the last ISIS stronghold in Syria amid a final push to clear the jihadist group from the war-torn country.

A CNN team in Syria witnessed airstrikes, explosions and mortar fire in Baghouz after the operation by the Syrian Defense Forces began about 6 pm local time.

SDF spokesman Mustafa Bali said on Twitter Sunday that its forces were engaged in "direct violent clashes" and that its planes were targeting weapons depots.

Men suspected of being ISIS fighters wait to be searched by the Kurdish-led Syrian Democratic Forces after leaving Baghouz last month.

Earlier Sunday, Bali tweeted that "the timeline ... for ISIS to surrender themselves is over" and that SDF forces were ready to "finish what is left in ISIS hands."

At its height, ISIS controlled huge swaths of territory in Syria and Iraq. The US-led coalition has been working for years to oust the group from cities and towns.

It was not clear Sunday how many fighters and civilians remained in the half-mile-square pocket under ISIS control in Baghouz.

Baquaz

- the timeline that we give it for ISIS to surrender themselves is over

- our forces is ready now to start and finish what is left in ISIS hands

- the SDF could rescue thousands of civilians during the past month/ plus thousands of IS members surrender to our forces

— Mustafa Bali (@mustefabali) March 10, 2019

Before the recent offensive started last month, SDF officials estimated that 1,500 civilians and 500 ISIS fighters remained, but as the assault got under way it became clear that the actual number was much higher.

On Tuesday about 500 ISIS fighters surrendered to SDF forces. The militants were among a wave of people fleeing fighting in the village, near the Iraqi border, which has been pummeled by US-led coalition airstrikes in recent weeks.

(CNN)