Horrifying video and images are emerging of Egyptian security forces beating protesters in Cairo, as reports of military units firing into the crowds continue to spread.

One such video, posted online this afternoon, is below. It's jarring. Watch at your own risk. 

Military police are using "rubber bullets, truncheons and tear gas," Matt Bradley and Tamer El-Ghobashy write for The Wall Street Journal, from Cairo. Protesters have responded by continuing their occupation of Tahrir Square and calls for the military council that has ruled the country since Hosni Mubarak was toppled to step aside. Protesters have set fires and thrown rocks and Molotov cocktails at the security forces in an ongoing battle that's now in its second night.