>> Iraqi forces and their American backers in Mosul
ised to take a strategic airport they believe will pave the way for a surge deeper into Islamic State stronghold. Preparing to strike but the risks multiply the further they advance. Reuters' Stephen Kalin is on the front line.>> They're expecting the western side to be much more difficult.
Because there are narrow streets which even Humvees can't even pass through. So, a lot of this is gonna have to be very close street to street fighting. And of course, there are hundreds of thousands of civilians still living inside of Western Mosul.>> The siege began over three months ago, and at first saw rapid gains for the government troops in the sparsely populated areas east of the Tigres River, even amid heavy fighting.
Tunnels left behind by the retreating militants and booby traps. But, the western side has a denser population. Humanitarian groups say those who live there are stuck between starvation if they stay and violence if they leave. Thousands of civilians have been killed or wounded since the fighting began. These families, just south of the airport, among the lucky ones.
>> The Iraqi forces are actually encouraging them to stay in their homes. Because taking 650,000 or even 800,000 civilians out of the city presents an enormous humanitarian crisis.>> If the troops can take the airport and a military base nearby, they hope to use them as staging areas for that westward assault.
Iraq's counterterrorism service seen here. Elite units trained by the Americans, expected to be the tip of the spear. One commander we spoke with said he expected little resistance entering the airport. Weakened by air and artillery strikes, the battle for Islamic State's heart grinding on.