Screenshot of @TravelGov tweet.

The situation surrounding Tahrir Square has deteriorated steadily throughout the day, with escalation moving from shouting, to fighting with sticks and stones, then to charges with horses and camels, next to Molotov cocktails and finally now confirmed gunfire and deaths.

From Al Jazeera English:

Heavy gunfire is being heard in Cairo’s Tahrir (Liberation) Square as pro-democracy demonstrators continue to defy curfew in the Egyptian capital.

Ambulances were seen heading to the area on Thursday morning and at least two fatalities were reported.

Protesters from the pro-democracy and pro-government camps fought pitched battles on Wednesday in Tahrir Square, the epicentre of demonstrations against Hosni Mubarak for the past nine days.

At least three people were reported to have died and more than 1,500 others injured in those clashes, according to officials and doctors quoted by the Reuters news agency.

An Al Jazeera correspondent, reporting from just outside Tahrir Square late on Wednesday night, said dozens of pro-Mubarak supporters erected barricades on either side of a road, trapping the pro-democracy supporters. They were gathering stones, breaking streetlights and using balaclavas to cover their faces, apparently in preparation for a fresh standoff with the pro-democracy crowd.

The United States State Department tweeted tonight on their @TravelGov account for all US citizens wishing to leave the country to report to the airport immediately.

Consider this to be an open thread for providing updates throughout the night in the US and a dawn in Egypt. Remember there is embedded live-streaming of Al Jazeera English on our Egypt coverage page.

Update: Multiple sources now (10:50 pm Eastern) confirm the death toll in the shooting is at least four.