'The Simpsons' to return to big screen

'The Simpsons' is heading back to the big screen - creator Matt Groening has confirmed a sequel to last year's hit movie.

The animated comedy went feature-length for the first time, and became a box office smash with earnings of more than $500m (€315.4m) worldwide, despite mixed reviews.

Now Groening is returning to Springfield for a follow-up - but he warns fans they have a long wait ahead, as the first film took four years to make.

"It will happen at some point, but I have no idea when," he said. "The first one took us four years - mainly because we don't like to work any harder than we usually do."

Last year marked the 20th anniversary of the Emmy Award-winning animated franchise.