YouTube star Christina Grimmie shot dead during autograph signing

YouTube star and former The Voice contestant Christina Grimmie has been shot dead in front of terrified fans as she signed autographs after a concert.

The 22-year-old was blasted by a gunman minutes after coming off stage at The Plaza Live in Orlando, Florida, in the early hours of Saturday, UK time.

Her brother tackled the gunman, who then shot himself dead, local police said.

Tributes poured in for the young singer from New Jersey, who finished third in the sixth series of the US version of the hit reality show in 2014.

Her Youtube videos, including cover versions of songs including Adele's Hello and Justin Bieber's What Do You Mean, have since gained millions of views.

Adam Levine, the Maroon 5 lead singer who was Grimmie's mentor on The Voice, posted a picture of them together before her death was confirmed, writing: "I'm sad, shocked and confused. We love you so much Grimmie. We are all praying hard that you can pull through this ... this just isn't fair."

Orlando Police Department said that Grimmie had performed with the band Before You Exit and stayed behind with them to sign autographs after the show which finished at 10pm local time (3am BST).

In a tweet the force said: "OPD was told suspect walked toward Christina and shot her. Christina's brother immediately tackled the suspect, who shot & killed himself."

It later added: "With deep regret, we have confirmed Christina Grimmie, @TheRealGrimmie has died from her injuries."

A statement on the official Twitter page for the US version of The Voice added: "There are no words. We lost a beautiful soul with an amazing voice. Our hearts go out to the friends, fans and family of @TheRealGrimmie."

Louisa Johnson, the winner of the 2015 UK series of The X Factor, was among those who paid tribute, saying: "Wow RIP #ChristinaGrimmie so sad."