Drivers are being asked to take extra care following a "large" diesel spill in Penrose, Auckland.

Northern Fire communications shift manager Scott Osmond said the spill was at the corner of Walls and Station Rds.

"We do not have information at this stage about what's caused it, but it is quite large and covers the whole intersection," he said.

Osmond said the roads were not closed, but said motorists were advised to "take serious care".