(CNN) -- For American travelers, this view of Egypt was not what they were counting on. Tear gas clouded the air as flames consumed city buildings -- a far cry from a day trip to the Great Pyramids they may have planned.
Heather (whose last name is being withheld for her safety), 23, watched chaos erupt on the streets below her Cairo hotel window.
"Initially, we were just in awe of all of the people coming across the bridge toward the square, then it started to become more violent," she told iReport.com. "There was a constant sound of police firing tear gas canisters, sirens and sounds of people pulling signs and benches from the street to drag over to the police lines."
Her father, George, captured video of protesters storming the Kasr Al Nile Bridge into El Tahir Square, where violence intensified by the hour.
"It was frightening to see the police regroup and retreat and to see the protesters throw things at those vehicles," she said. "The police have definitely escalated the situation and began by firing tear gas at the protesters."
Heather and George aren't the only tourists stuck inside their hotel rooms.
An employee at the U.S. State Department said representatives have been "on the phone with Americans in Egypt all day."
The State Department has issued a travel alert urging tourists to avoid Egypt due to dangerous conditions.
Those already stranded in the country shouldn't leave hotels until the situation stabilizes, the alert stated.
Some airlines are halting flights to Cairo indefinitely.
Delta Air Lines' last flight from Cairo is scheduled to depart on Saturday, said spokeswoman Susan Elliot. American Airlines and British Airways are allowing customers to change ticket destinations for free until Monday.
The State Department's travel warning said the U.S. Embassy may be blocked off for security during demonstrations and cautioned citizens against going to the embassy during the turmoil. The alert provides contact numbers for security updates and travel information.
"Right now, we can only tell Americans to stay in place," a State Department representative said.
The current travel alert expires on February 28.