[Ammi]

Chris Brown has been ordered to spend three months in rehab after it was revealed he threw a rock through his mother's car window.

The Grammy winner tossed the rock through the window on November 10 after a joint counselling session with his mother, during which she suggested the singer remain in treatment.

Details of the incident were revealed in a letter submitted to the court by the rehab facility, which discharged him after the outburst. The facility's name was not included in court filings.

The letter said: "Mr Brown proceeded to walk outside and pick up a rock and threw it through his mother's car window and it shattered."

The singer was discharged because he had signed a contract agreeing to refrain from violence while in treatment.

Superior Court Judge James Brandlin also added additional rules for Brown in the coming months, requiring him to perform at least 24 hours of community labour a week and to submit to drug testing

Brown and his lawyer have agreed to the terms, which were suggested by probation officials who are overseeing Brown's sentence for his 2009 beating of then-girlfriend Rihanna.

The singer voluntarily checked into rehab for anger management treatment on October 29, just days after he was arrested in Washington DC, when a man accused Brown of punching him.

The incident and the resulting misdemeanour assault charge could still trigger a probation violation that could lead to more sanctions against Brown.

Brandlin ordered probation officials to collect more details on the Washington arrest and report back to him before a hearing on December 16.

A prosecutor did not call for Brown's probation to be revoked at Wednesday's hearing, but said she was awaiting more details.

Brown appeared in court with his girlfriend Karrueche Tran and only spoke once to acknowledge he agreed to the terms imposed by the judge