A days-long natural gas leak has forced a partial evacuation at one of the biggest oil fields in North Slope, Alaska, media reported on Tuesday, with one local official saying the gas was still leaking.

The leak was discovered Friday at a drill site in ConocoPhillips' Alpine oil field, the company confirmed late Tuesday.

The gas was still leaking on Tuesday, said Rosemary Ahtuangaruak, mayor of Nuiqsut, an Inupiat village about seven miles south of the oil field. As of now, it is unclear if there is an effect on the village of about 490 people, she said.

ConocoPhillips evacuated non-essential workers at the drill site and at the Alpine Central Facility, the company said in a statement.

"There are no reports of injury or environmental impact to the tundra or wildlife," the company said, adding that Conoco is monitoring air quality at the pad where the leak took place.

The Alaska Oil and Gas Conservation Commission, a state regulatory agency, is monitoring the leak and ConocoPhillips' response, an official said.

"Based on its investigation to date, the Commission is unaware of any threats to public safety," Jeremy Price, chairman of the commission, said in a statement, adding that due to the open investigation the commission could not comment further.

ConocoPhillips did not respond to queries as of Tuesday afternoon.

In Nuiqsut, residents are uneasy despite the official assurances, Ahtuangaruak said. "We have community members that have reported smelling gas since Friday," she said.

Since Nuiqsut is edged by oil development, there are longtime concerns about chronic air pollution from the operations, Ahtuangaruak said. Over the years, there have been "gains and losses" in local efforts to better control air pollution for residents, many of whom suffer from respiratory problems due to poor air quality, she said.