Bruno Mars' mother has had a serious heart attack.

The 'Locked Out Of Heaven' hitmaker's mother Bernadette Hernandez, 55, was rushed to hospital in Honolulu, Hawaii on Friday night (31.05.13) where she is reportedly still in a critical condition.

Family friend Anita Sojot told Star magazine that the family are gathering to be at Bernadette's bedside.

She said: ''Bernadette is in hospital and the grandkids are all here, I'm looking after them. The family is on its way here right now and we are going to discuss what to do next.''

The 27-year-old Grammy-winner has been very open about his love for his mother in the past and even wrote a song called 'I Love You Mom' about her, in which he refers to her as a ''superstar'' and ''my favourite girl.''

Bruno, whose real name is Peter Gene Hernandez, also has Bernadette's name tattooed on his shoulder.

The singer, who is set to kick off on his Moonshine Jungle world tour in Washington D.C. on June 22, has yet to comment.