Guardians of the Galaxy to star in Avengers 3

Vin Diesel also stars in the Fast and Furious franchise

The third Avengers film will feature superheroes from Guardians of the Galaxy, actor Vin Diesel has revealed.

The Hollywood star, who voices talking tree Groot in Guardians, let the news slip during a Facebook Live video on Friday.

Vin Diesel called the planned Avengers mash-up "incredibly exciting".

Guardians also starred Chris Pratt, Zoe Saldana and Bradley Cooper. Avengers: Infinity War is expected to include Marvel characters from across 18 films.

The movie will be released in May 2018.

A spokeswoman for Disney did not immediately respond to Diesel's comments.

Michael Rooker plays Yondu in Guardians

Guardians of the Galaxy Vol. 2 is due in cinemas next May, reuniting the original ensemble cast along with Michael Rooker, Glenn Close and Karen Gillan.

Pom Klementieff joins the cast as alien hero Mantis, along with Kurt Russell, Sylvester Stallone and Sharon Stone.

When the film wrapped in June, Pratt said: "This is going to be the greatest spectacle film of all time."

The first film is one of Marvel's most successful movies yet, making more than $771m (£540m) at the worldwide box office.