Firefighters are staged outside a Lehigh Valley natural gas power plant after an explosion sparked a blaze at the facility Sunday evening, officials said. A transformer exploded just after 8 p.m. at Talen Energy's Lower Mount Bethel power plant along Depues Ferry Road in Lower Mount Bethel Township, Northampton County emergency dispatchers tell NBC10. Photos posted by people living near the plant, which sits next to the Delaware River, showed intense flames and thick black smoke billowing into the air. Firefighters were forced to stay back from the fire because of electrocution concerns when they first arrived on scene. They were spraying fire-retardant foam on the blaze from afar, officials said. The fire is contained to the transformer on the plant's grounds. The plant burns natural gas to produce electricity, according to Talen's website. Officials said the generation facility is not burning. There are no reports of injuries and residents have not been evacuated. Todd Martin, a spokesman for Talen Energy, said the plant has been completely shut down and will remain closed for the foreseeable future. Martin said there's no danger to the public or employees. "[It] will will take time to investigate and evaluate to ensure whatever has happened will not happen again," he told NBC10. "An investigation is ongoing into what caused the units involved to stop operation tonight." Martin said the company will work with state regulators on an investigation into the incident. The plant's shut down has not resulted in power outages, officials said.