Billie Eilish sparked concern from fans after showing off mysterious bite marks after stripping down to her bikini.

The Lunch singer, 22, shared a series of snaps from her July 4 Independence Day weekend for fans on instagram.

And the Oscar winning hitmaker even included a rare bikini shot as part of the collection of images.

Billie looked carefree and relaxed as she posed in a pink halter neck bikini top with a towel around her waist.

She held a firework aloft as she stuck out her tongue for the cheeky snap.

“The boobs are back!” posted one admirer, while another branded her a “hottie”.

But it was two other photos in the album that caught fans attention more.

One showed Billie with two fresh-looking round bite marks on her arms.

And in another they appeared to have turned into bruises as she took a mirror selfie with a pal.

“Wait are those bite marks?” commented one fan.

“Is she…okay??? Those bite marks look nasty,” added another.

Despite the marks, Billie certainly seemed to be having a whale of a time during the holiday weekend in the US.

As well as larking around with fireworks in a garden, she appeared to enjoy time with a pal on a climbing wall.

One picture she uploaded showed her hugging a pal on the floor while wearing special climbing shoes.

Another shot showed her going make-up free as she showed off her messy hair, while the final shot in the collection featured a bizarre Clown seat in the back of the car.

And many of her army of devotees lapped it up, saying they wanted even more of an insight into their idol’s downtime.

One commented: “Billie’s the only celebrity i’ve ever wanted vlogs from, she’s always having some sort of amazing adventure.”

“So pretty i might actually stop breathing,” chipped in another.