08:59 AM EST, 01/16/2025 (MT Newswires) -- Core Natural Resources ( CNR ) said Thursday it is temporarily sealing the active longwall panel at its Leer South mine to address isolated combustion-related activity.

The company said it is working with regulators and implementing measures to manage the issue. Core Natural said that development on future longwall panels will progress during this period.

Longwall mining is expected to resume mid-year and continuous miner development within three months, the company added.

Shares of the company were down 1.4% in recent Thursday premarket activity.