AceShowbiz -

Londoners lining up at Empire Leicester Square on June 2 screamed for Brad Pitt and Angelina Jolie as the two lovebirds, along with their sons Maddox and Pax, arrived at the premiere of "World War Z". Making her first public appearance since undergoing a double mastectomy, Jolie looked lovely in a floor-length Saint Laurent black dress with a see-through front panel.

Pitt, who came in his favorite black ensemble, was later joined by his co-stars Mireille Enos and Peter Capaldi. Spotted hitting the black carpet too were celebrity guests Idris Elba, Tom Ford, Rita Ora, Natasha Bedingfield, Gemma Whelan and British band Lawson.

At the event, Pitt told reporters that there's a possibility of turning the film into the start of a trilogy. "There is enough in the book to pick up if this [film] works," the actor said before director Marc Foster added, "We approached it with the thought that this film must work. And if it is a success, we will see and [maybe] set it up as a trilogy."

Following the Sunday premiere, English rock band Muse, which contributed a song to the film's soundtrack, performed live at Horse Guards Parade Ground, St. James' Park.

"World War Z" introduces Pitt as a United Nation employee named Gerry Lane who travels around the world to try and find a cure for the zombie virus and save his family and the world. The action thriller will arrive in U.S. theaters on June 21.