Jamie Lynn Spears allegedly wielded a knife during a fight last weekend.

The 23-year-old star, who is the younger sister of Britney Spears, reportedly used a serrated bread knife to protect a female friend after she got into a brawl with another girl at the Pita Pit in Hammond, Louisiana.

A law enforcement source said the country singer, who has a six-year-old daughter, Maddie, with ex-boyfriend Casey Aldridge, reached for the closest weapon to defend her friend after she got hit on the head with a bottle when they made a late night visit to the eatery for food.

The insider said the blonde beauty, who previously admitted she is very protective of her loved-ones, dragged her friend to safety behind the sandwich counter and grabbed the first weapon she could find, a long knife, and started waving it around in a desperate bid to stop the fight.

When police arrived at the scene, Jamie Lynn's friend decided not to press charges and no one was arrested, according to gossip website TMZ.com.

The 'How Could I Want More' hitmaker got married to her businessman boyfriend Jamie Watson of over three years last March.