SYDNEY/PARIS (Reuters) - French police reinforcements have started arriving in New Caledonia as part of a massive operation to regain control of the capital Noumea, the top French official in the Pacific island territory said on Friday.

The number of police and gendarmes on the French-ruled island will rise to 2,700 from 1,700 by Friday evening.

After rioting that began on Monday resulting in four deaths and hundreds of arrests, Thursday night was relatively calm, France's High Commissioner Louis Le Franc told reporters in a televised press conference.

There were still points of confrontation and concern in the city of Noumea, he said.

Operations to supply food and medicine to the public will begin with teams, including specialists in mine clearing, removing road barricades that have been booby trapped by activists, he said.

"Reinforcements will arrive massively, immediately (and will be) deployed to control the areas which have escaped our control in recent days... to reconquer all the areas of the urban area which we have lost," he said.

Rioters angry with an electoral reform have burnt businesses, torched cars, looted shops and set up road barricades over three days, cutting off access to medicine and food, authorities said.

"Our calls for calm, peace and reconciliation are beginning to be heard... It is important that those who are at the origin of the clashes, of the blockages, hear this," Le Franc said.

The New Caledonia government said in a statement on Friday the island has stocks of food for two months and the problem is distribution.

France has declared a state of emergency on the island, put at least 10 people under house arrest and banned TikTok.

The rioting erupted over a new bill, adopted by lawmakers in Paris on Tuesday, that will let French residents who have lived in New Caledonia for 10 years vote in provincial elections. Some local leaders fear the move will dilute the indigenous Kanak vote.

Electoral reform is the latest flashpoint in a decades-long tussle over France's role in the mineral-producing southwest Pacific island some 1,500 km (930 miles) east of Australia.

The Pacific Conference of Churches on Friday joined regional inter-governmental groups in calling for France to withdraw the constitutional bill, and said the United Nations should lead a dialogue mission to New Caledonia.

In a statement, the churches said there had been a breakdown in dialogue between the French government and Kanak people.

(Reporting by Kirsty Needham in Sydney, Lucy Craymer in Wellington and Camille Raynaud in Paris; Editing by Raju Gopalakrishnan)

By Kirsty Needham and Camille Raynaud