French police in New Caledonia arrested protest and pro-independence Caledonian Union leader Christian Tein on Wednesday.
Local media reported the arrest of eight people including Tein took place in a police operation at the party headquarters on Wednesday morning.
Many businesses, shops and the Noumea town hall closed down afterward out of concern of further unrest.
Nine people died, including two police, in violent protests that swept New Caledonia last month after France voted to approve reforms to allow thousands more French residents who have lived in the French Pacific territory for 10 years to vote.
Indigenous Kanaks fear it will dilute their vote and make it harder for any future referendum on independence to pass, while Paris says the measure is needed to improve democracy.
Tein leads a branch of the Caledonian Union called the Field Action Coordination Cell (CCAT), which organized protest barricades across the capital Noumea that have disrupted traffic, movement and food supplies.
He was among the pro-independence political figures who met with French President Emmanuel Macron during his lightning visit to New Caledonia last month.
In a statement, Caledonian Union President Daniel Goa urged calm among CCAT protesters and told youth not to respond to what he said was a "provocation."
The French High Commission said in a statement that the city center was "free and secure," as media reported many cars leaving.
The New Caledonia prosecutor's office did not immediately respond to a request for comment.
Macron said last week he had suspended the voting reform, however, pro-independence groups want it completely withdrawn before dialogue over the political future of the island can restart, saying they cannot otherwise persuade young protesters to leave the barricades.
New Caledonia's international airport reopened this week, although a curfew is still in place and several thousand French police reinforcements remain.