Maré, with a population of 6,000 people, sits in the New Caledonia archipelago, part of France's overseas territories. The islands are a popular exotic holiday destination for many French people.
Islanders have been protesting for over 10 days about price rises at the local Air Calédonie airline. The protest is estimated to have caused losses of €1.2 million, taking the airline to the brink of bankruptcy.
Trouble was sparked on Saturday when a group arrived at the airport and tried to break up the original protest. The group of 300 people had come from the Guahma district where the airline's president, Nidoish Naisseline, is the chief.
The two groups of about 300 each fought initially with stones. Later in the afternoon gunfire was reported and four men were killed. At least a further 23 were injured.
"Maré has had a nightmare day," said the island's high commissioner, Albert Dupuy.
The French minister for overseas territories, Mari-Luce Penchard, hurried back to Paris to hold urgent talks.
"It's essential that a way is found to establish a dialogue so that we can return to a a situation of calm in Maré," she told news channel i-télé.
The minister's plans for dialogue include mediation by religious groups. She claimed in a press conference that the dispute goes much deeper than the issue of air fares and is also linked to land ownership issues.
She also said she has obtained agreement to remove the barricades around the airport so that police can ensure access from Monday.
Nicolas Sarkozy is expected to visit New Caledonia at the end of August. There are plans for a referendum in the area, which is officially known as a "special collectivity", some time between 2014 and 2019.