The directing duo posted a teaser photo on social media marking the beginning of "Avengers 4" shoot.
They shared an image featuring a glove with four fingers extended.
Marvel has yet to reveal the title for "Avengers 4".
The official cast for the film also is being kept under wraps.
However, Josh Brolin and Jeremy Renner have already confirmed that they would be returning for the fourth 'Avengers' movie.