The French high commission in New Caledonia says plans to fight gangs are being advanced with new laws now coming into effect.
In a statement, it says to curb violence by groups and reduce attacks on people performing public functions, it will now be a crime punishable with prison, if a person joins a group with the intention to use violence.
It says this can be sanctioned with a one-year jail sentence and a 20,000 US dollar fine.
The high commission says wearing a hood to disguise one's face while committing a crime is considered as an aggravating factor.
It also says it is now a crime to enter injustifiably school premises because staff need protection.
The announcement comes after a series of violent incidents in the Noumea area.