Comic book fans decked out in costumes of their favourite characters have flocked to San Diego for this year's four day Comic-Con expo.

The annual celebration of comic books and related pop culture kicked off Thursday and wraps up Sunday — after four full days of film screenings, autograph signings and expert panels.

Comic-Con International: San Diego started in 1970 as a one-day mini event when three fans banded together to create southern California's first comic book expo. That event, which featured only two special guests, drew about 100 attendees.

More recently, nearly 130,000 fans came to check out hundreds of workshops and panels, and to meet some of the hundreds of pop culture celebrities.

So far this year, stars from X-Files, Dexter and Star Wars have interacted with the eager crowds.

The Associated Press will be covering the event live below starting at 1 p.m. ET.

With files from the Associated Press