CAIRO (AP) -- Egyptian security forces are firing tear gas to disperse around 3,000 protesters, some of whom are throwing rocks and firebombs, in Cairo's Tahrir Square.
Eyewitnesses say the clashes began outside the Interior Ministry on Tuesday evening between families of protesters who were killed during the Egyptian revolution that ousted longtime rule Hosni Mubarak in February.
It was not immediately clear what sparked the clashes, but witnesses say the demonstrators began throwing rocks at the ministry building.
Security forces responded by firing tear gas and deploying troops to seal off the roads around the ministry and push the demonstrators back toward Tahrir Square.
The clashes are still going on, with clouds of tear gas engulfing the square.