Country star Miranda Lambert isn't about to drop her tweet war with R&B singer Chris Brown after he took aim at her for criticising his return to the Grammy Awards stage on Sunday night - she has fired off another salvo.

Outspoken Lambert took to Twitter on Monday to express her outrage at Brown's performances at the awards ceremony on the third anniversary of his of his infamous fight with ex-girlfriend Rihanna, which landed him in court on assault charges and resulted in a hard labor sentence and five years' probation.

Convinced he shouldn't have been there, the pretty singer, whose parents ran a shelter for abused women when she was growing up, raged, "Chris Brown twice? I don't get it. He beat on a girl... Not cool that we act like that didn't happen."

Defiant Brown, who also picked up a Best R&B Album Grammy on Sunday, turned on Lambert and others on Tuesday via Twitter when he wrote, "Hate all u (you) want becuz (because) I got a Grammy now! That's the ultimate f**k off! I'm back so watch my back as I walk away from all this negativity."

Lambert picked up the social networking row on Wednesday when she responded, "Oh and one more thing for all who are asking....I have a Grammy too."