Police were called after Britney Spears shared a video of herself dancing with knives.

The 'Toxic' singer sparked alarm with her Instagram posts earlier this week, and cops have now confirmed they carried out a welfare check at her home following a call from someone who wanted to remain anonymous but officers were able to confirm they had a relationship with the 41-year-old pop star and were not just a "fan".

Captain Dean Worthy of the Ventura County Sheriff's Office told the New York Post newspaper's Page Six column that a sergeant who has dealt with numerous incidents involving Britney over the years attended the call.

He added: “Somebody close to Britney had seen the video posted on social media, where she’s dancing and twirling with knives in her hands, and they were really concerned for her mental well-being."

Cops spoke to the security team at Britney's home in Thousand Oaks, California, via the intercom and were told the 'Gimme More' singer was "fine" and there was "nothing going on".

The policeman said: “They didn’t want to let the officer in to see her physically."

Britney later took to Instagram again and urged fans not to "worry" about her, despite sporting a bandage following her first knife dance, insisting the props were fake and she was just taking inspiration from Shakira's performance at the MTV Video Music Awards (VMAs) earlier this month.

She wrote alongside a new knife-wielding dance video: “I know I spooked everyone with the last post, but these are fake knives that my team rented from Hand Prop shop in LA.

“These are not real knives. No one needs to worry or call the police. I’m trying to imitate one of my favourite performers Shakira … a performance I was inspired by !!!

“Cheers to us bad girls who aren’t afraid to push boundaries and take risks [nail painting emojis] (sic)"

TMZ has reported those responsible for Britney under her controversial 13-year conservatorship made a list of recommendations when it ended, with one point being to keep knives away from her.

The outlet said: “Sources have told us Britney sees knives as a type of protection... and we were told she keeps them all around her house, including her bedroom.”