Credit: Robert Marquardt/Getty

Tough, tense times for Scarlett Johansson.

On Friday Dec. 10 -- four days before she and Ryan Reynolds confirmed their split -- a witness spotted the actress, 26, storm angrily into the Manhattan apartment building where she and Reynolds lived.

Wearing a baseball cap, Johansson looked "miserable," the observer tells the new Us Weekly.

"She was screaming into her phone, referring to someone as a 'jerk.' She looked really pissed off."

It's unclear who was on the other line sparring with the Iron Man 2 star, but both Johansson and Reynolds, 34, are licking their wounds following the demise of their 2-year marriage.

"Scarlett has been unhappy for a while and wanted the separation," a source tells Us, explaining that the couple's busy film schedules kept them apart for too long.

For now, Johansson has the support of her friends -- and lots of sun and surf. She was photographed kicking back with pals in Jamaica on Wednesday.

Read more about the week's most talked-about split in the new Us Weekly, out now.