Since being launched this summer, Facebook Live has been used to put up a variety of popular video offerings, such as tutorials on makeup and food. There have even been interviews with rock-music legends.

But the live streaming of war — with viewers able to watch video feeds of the so-called Battle for Mosul as it got under way — seemed like a new direction for the social-media platform FB, +2.66% . Be warned, of course, that at any moment this could turn into challenging viewing, with real gunfire and possibly death appearing unfiltered.

Monday marked the start of a military offensive by Iraqi and Kurdish forces who are trying to recapture the city of Mosul from Islamic State. Iraqi army troops were said to be moving in on the edge of the northern edge of the city, which has been controlled by Islamic State for more than two years.

A live video feed on the Al Jazeera English Facebook page kicked off about eight hours ago, showing a distant battlefield, up-close shots of jittery soldiers holding flags and visibly wincing at gunshots and plumes of smoke. Running audio commentary is, as of now, in Arabic only.

Other streaming views were showing up on YouTube and Periscope.

Some watched in awe, while others were clearly uneasy with where technology has taken us — watching a high-stakes battle that the United Nations has already warned could leave up to 1 million people homeless. (Mosul is nominally home to some 2.5 million inhabitants.) That nearly equals the population of Austin, Texas, and just about matches the population of San Jose, Calif., according to 2014 statistics.

It’s the social-media generation meets war, said some:

Since Facebook plunged into live streaming this summer, some of the most popular offerings have included “Tipsy Tricks,” which features wine and makeup tips from Benefit, and Tastemade’s addictive real-time cooking demonstrations in a doll-house-sized kitchen. And who could forget the record-busting “Chewbacca mom,” who literally laughed while wearing a mask and shot to Facebook and internet fame this spring?

So it remains to be seen how much real-time war Facebook fans can stomach.

Save the Children recently estimated that a half-million children are in the line of fire in Mosul. If they stay, they risk being caught in the crossfire and becoming collateral damage in airstrikes, the charitable organization observed. “If they flee, they face being killed by land mines, captured or shot by IS fighters.”