Robert Downey Jr., 'Avengers: Infinity War' directors try to maintain secrecy

No spoilers!

Star Robert Downey Jr. is joining the directors of "Avengers: Infinity War" in asking fans to maintain secrecy.

The star tweeted "no spoilers please." He added #ThanosDemandsYour Silence. Thanos is the fictional Marvel Comics villain who will be portrayed by Josh Brolin in the movie. Downey plays Iron Man.

Directors Joe and Anthony Russo went on Twitter to tell fans they would be screening a limited amount of footage prior to the film's release on April 27. They say "only a handful of people know the film's true plot."

They wrote: "We’re asking that when you see 'Infinity War,' in the coming months, that you maintain the same level of secrecy so that all fans can have an equal experience when they watch it for the first time. Don’t spoil it for others, the same way you wouldn’t want it spoiled for you."

The Associated Press contributed to this report.