Officials in a northern Japanese city have urged residents to evacuate their neighborhood after a natural gas leak killed at least two people Friday, according to The Associated Press. Around 178 people in the northern Hokkaido prefecture (state) city of Kitami were urged to evacuate to a nearby elementary school after the leak in residential gas lines occurred around 1:30 p.m. (0430 GMT), city official Osamu Oe said. At least four people were injured and taken to the hospital for treatment, but their conditions were not immediately known, said local fire department official Takao Yokoyama. The fire department responded after local utility company Hokkaido Gas Co. notified it that local residents were complaining of the smell of gas in their neighborhood, Yokoyama said. Local police have established an off-limits area, while official work to determine the exact location and cause of the leak, he said. The leak has not yet been contained, he added. Gas company officials were not immediately available for comment. Kitami is approximately 1,000 kilometers (620 miles) northeast of Tokyo.