Jim Carrey has refused to support 'Kick-Ass 2' because of its ''level of violence''.

The actor is set to star in the action blockbuster this summer, but has decided to withdraw from promoting the film following the Sandy Hook school shootings last December.

He wrote on Twitter on Sunday (23.06.13): ''I did Kickass a month b4 Sandy Hook and now in all good conscience I cannot support that level of violence.

''My apologies to others involve with the film. I am not ashamed of it but recent events have caused a change in my heart. (sic)''

Jim, 51, is a staunch supporter of gun control and was shocked by the shootings that took place at Sandy Hook Elementary School in Newtown, Connecticut, in December 2012, in which 20 children and six adults were killed.

The actor has drawn criticism for his controversial comments, however, with 'Kick-Ass' producer Mark Millar claiming Jim was aware the film would be incredibly violent when he signed on.

He wrote on his Millarworld.com website: ''As you may know, Jim is a passionate advocate of gun-control and I respect both his politics and his opinion, but I'm baffled by this sudden announcement as nothing seen in this picture wasn't in the screenplay eighteen months ago.

''Yes, the body-count is very high, but a movie called 'Kick-Ass 2' really has to do what it says on the tin. A sequel to the picture that gave us Hit-Girl was always going to have some blood on the floor and this should have been no shock to a guy who enjoyed the first movie so much.''