Amanda Bynes unleashed another Twitter tirade, this one against pop star, Rihanna, who apparently was the victim of domestic violence because she is ugly.

According to E! Online, Bynes didn’t skip a beat in the three days since her arrest for drug possession, as she’s back to spewing her rambling thoughts – which have been quickly deleted – on Twitter.

Earlier today, she tweeted: “@rihanna Chris brown beat you because you’re not pretty enough.”

Bynes was referring to the incident in 2009 when Rihanna was hospitalized after a physical altercation with her then-boyfriend, R&B artist Chris Brown. Brown was charged with felony assault.

Bynes continued, “@rihanna no one wants to be your lover so you call everyone and their mother that I almost named my new dog Rihanna.”

Unwisely, Rihanna engaged in Bynes’ online antics and tweeted back: “Ya see what happens when they cancel Intervention?”

This indirect dig opened up the floodgates. “@rihanna unlike ur fugly faced self I don’t do drugs! U need the intervention dog! I met ur ugly face in person! U aren’t pretty u know it!” Bynes wrote.

E! reports that Rihanna didn’t bite again after that.

This isn’t the first time Bynes has thrown below-the-belt insults on Twitter.

Earlier this month, Bynes called model-actress Jenny McCarthy “ugly” and an “old lady” who needed to “shut the f*ck up!” because McCarthy passed along a false story that cops had been summoned to Bynes’ house, Yahoo! reported.

McCarthy recently made amends with an apology, but there’s no telling how the Rihanna spat will turn out.