The NBA will challenge a decision to reduce by 10 games a 25-match ban on Indiana Pacers Jermaine O'Neal for his part in an ugly brawl during a clash with the Detroit Pistons last month.

Arbitrator Roger Kaplan reduced O'Neal's ban on Wednesday while ruling that Ron Artest will remain suspended for the remainder of the season for fighting with fans and upholding suspensions on Stephen Jackson (30 matches) and Anthony Johnson (five).

The NBA responded by saying it would go to a US federal court to challenge Kaplan's decision to reduce O'Neal's ban, arguing the arbitrator had no jurisdiction to overturn the suspension.

According to the NBA, all appeals in this matter must be made to commissioner David Stern and not an arbitrator.

Television reports said the NBA had already filed a lawsuit in US District Court with a hearing scheduled for Thursday.

The five Pacers and several fans face criminal charges stemming from the violent melee that threatened to escalate into a full scale riot.

The brawl started after Artest fouled the Piston's Wallace with less than a minute of the game remaining and the Pacers leading 97-82.

Wallace responded by pushing Artest in the face, which led to players pushing and shoving near the scorer's table.

After Artest had liquid thrown over him he bolted into the stands and was followed by Jackson. Both players threw punches at spectators and O'Neal also punched a fan who ran on to the court.

Television pictures showed players beating fans and terrified, crying children huddling in their parent's arms. 

(Agencies)