LVIV, Ukraine – Hollywood actress and U.N. humanitarian Angelina Jolie made a surprise visit to the western Ukrainian city of Lviv on Saturday.

During her visit, Jolie hastily exited a train station “as air-raid sirens went off” in the city, according to video tweeted by Bulgarian journalist Christo Grozev, an investigative journalist for Bellingcat, and by Reuters.

In the video Grozev shared on Twitter, which has been viewed more than 200,000 times, the actress appears to pick up speed as she walks out of the station with a group of people. Sirens can be heard in the background.

After crossing a street, she smiles and waves to a man recording her on his phone. “Are you afraid?” he asks her. Off-camera, Jolie responds, “No, no, I’m OK.”

It’s unclear when the video was taken. USA TODAY has reached out to Jolie’s representative for comment.