Hundreds of barrels of oil have leaked into the Yellowstone River in the United States after an ExxonMobil operated pipeline ruptured.

As many as 1,000 barrels of oil are feared to have leaked into the river following the accident, which occurred downstream from Yellowstone national park, a major tourist attraction in the US.

ExxonMobil confirmed it took half an hour to isolate the fault and close the pipeline.

Residents in the surrounding area were briefly evacuated, but were later allowed to return to their homes.

An investigation has now been launched.

“We recognise the seriousness of this incident and are working hard to address it,” the company said in a statement.

“Our principal focus is on protecting the safety and health of the public and our employees,” it added.