WELLINGTON (Reuters) -New Caledonia mobilised security forces, closed its international airport and imposed a curfew in the capital after protests turned violent and police were attacked, the French High Commission said on Tuesday.

The unrest prompted New Zealand to postpone a visit this week by Foreign Minister Winston Peters, which a spokesperson said would allow authorities to focus on the current situation.

"We are aware of events in New Caledonia, and hope that peace and calm will prevail," the spokesperson said.

The protests and violence happened on Monday ahead of a vote in the French National Assembly on changes to the New Caledonian constitution.

Video showed the police patrolling the streets among burnt out cars and plumes of smoke, after protesters had set up blockades on key roads on Monday.

The commission said in a statement that significant disturbances in the capital, Noumea, and surrounding townships were ongoing.

It said security forces had been mobilised, all gatherings had been banned in the greater Noumea area, and a liquor ban had been put in place.

It said the curfew would be imposed from 6 p.m. (0700 GMT) on Tuesday until 6 a.m. on Wednesday in Noumea.

The international airport in Noumea had been closed and all commercial flights cancelled, the airport operator said in a statement on Tuesday.

(Reporting by Lucy Craymer and Kirsty Needham; Editing by Sonali Paul and Neil Fullick)

By Lucy Craymer