ANCHORAGE, Alaska (AP) — A federal official says crews in Alaska are ready to shut down an oil well that is misting natural gas on the frozen North Slope, but officials say it's too unstable for responders to get close.

The Environmental Protection Agency says a crack in a BP wellhead near Deadhorse sent up mist of crude oil Friday before it froze over and an initial leak stopped.

"Based on an overflight with infrared cameras, the release appears to be contained to the gravel pad surrounding the wellhead and has not reached the tundra," BP spokesman Brett Clanton said Saturday.

A response team made up of state and federal energy officials and BP personnel was not able to secure the well Friday night or Saturday due to safety concerns.

Two leaks have been identified on the well, one near the top and one further down the well assembly, BP said. The upper leak was misting oil in conjunction with leaking natural gas, but activation of a surface safety valve stopped the release.

The bottom leak was releasing gas and a small amount of crude oil, the energy giant said.

It's unclear how much has vented, but nearby workers have been evacuated and native Alaskan villages dozens of miles away have been notified.

No injuries have been reported.

The agency says the initial oil release may have affected an area of about 1 ½ acres. There were no reports of damage to wildlife.