Britney Stars and Jamie Lynn's social-media feud continued Monday, as the pop star apparently called out her sister for being "so cruelty" in an Instagram post.

Spears, 40, shared a video of her working out. The "Toxic” singer wore a bright yellow crop top and black shorts.

"So, I wanted to repost it because d----n!!! "Y'all comments were so nice I might as well offer another round of this video without my voice. As I repost this, I get laughed at by most.
Jamie Lynn was then allegedly hit by her, mentioning the name of Jamie Lynn's memoir "The Things That I Should Have Said"

"I might gain empathy for myself and say THE THINGS ..... First, F-K YOU. What's the big LETTER TALK? YOU THINK YOU ARE IMPORTANT! AGAIN F-K YOU!... If that's too offensive for you, you can take some salt [salt Emoji] and sprinkle it on your a-es. You people are so cruel it might be necessary to do some cleansing !!!! Pssss KEEP SMILING."

Fox News Digital reached out to Jamie Lynn and Jamie Spears for clarification but they did not immediately reply.

Before and after Jamie Lynn's memoir, Spears was critical of her sister online. In a recent Instagram post, Spears called Jamie Lynn "scum".

"The nerve of your to sell a book and talk s---t, but your f---ing lying just as you lied about Alexa Nikolas I wish you would do a lie detector test so that all these people can see that you are lying about me !!!! I wish the all-powerful, Lord could show the whole world that you are lying and making money from me !!!! Jamie Lynn, you are scum," Spears wrote.

Jamie Lynn and Spears' strained relationship was made public by Jamie Lynn in the last year, as Jamie sought to end her conservatorship.
The pop star called out her relatives in court and social media, accusing them of failing to free her from her 13-year-old court order.