She blames the paparazzi for creating mayhem at a school where she was shooting scenes for the movie.
Her bodyguards — who said they were trying to stave off photographers — were accused of physically blocking parents from picking up their children. The gates of the school had been locked during filming, and a fracas took place when they were opened.
"It was not the film production that caused chaos," Jolie, 31, tells Entertainment Weekly magazine. "We were only guilty of bringing the paparazzi."
"A Mighty Heart," directed by Michael Winterbottom, is based on a memoir by Mariane Pearl, widow of Daniel Pearl, a reporter for The Wall Street Journal who was abducted and murdered in Pakistan in 2002 while researching a story on Islamic militancy.
Photos: On Location With Angelina
Jolie plays Mariane Pearl and Dan Futterman plays Daniel Pearl. The film is scheduled for release in June by Viacom Inc.'s Paramount Vantage.
"The story unfolds like a mystery," Jolie says. "You've got people collecting clues and trying to solve what happened. But it's also very real and personal. We didn't want it to be too melodramatic or too polished. We didn't want it to be a typical movie."
Winterbottom's shooting style is a little like the taping of a reality show. He uses handheld cameras, encourages as much improvisation as the story line allows, and follows his actors wherever they go.
"It could get intense. Michael and I would have disagreements over where he could follow me," Jolie says. "I just needed to know that if things got too heavy, there'd be a place for me to cry by myself."
Jolie won an Oscar for 1999's "Girl, Interrupted."