Madonna collapses during Sofia gig?

Madonna collapsed twice during a concert in the Bulgarian capital of Sofia on Saturday, it has been claimed.

According to The Sun, the singer briefly lost consciousness during 'Holiday' and later passed out offstage during a rendition of 'Spanish Lesson'.

A source told the newspaper: "Madge was really worried backstage. She had to sit down for a longer break than usual between songs.

"She refused to end the show or take a break after the 'Holiday' dizzy spell. It turns out she's suffering from exhaustion. She is anaemic."

They added: "She was advised to postpone the last two shows in Israel for a few days, but logistics and stubbornness stopped her. She'll do them then take some rest."

Video footage shows Madonna seemingly struggle to maintain her balance during 'Holiday', though it is unclear if her movements are part of her dance routine.

The pop superstar has since performed in the Israeli city of Tel Aviv.