(Reuters) - Phillips 66 reported that a leaking oil storage facility released an unknown amount of oil into the facility and surrounding area at its 247,000 barrel-per-day Alliance refinery in Belle Chasse, Louisiana, according to a filing with national pollution regulators.

The incident was discovered at 1308 (local time) on Sunday, the filing said.

The refinery, which was shut and without power as of August 30, had also seen flooding after storm Isaac.

(Reporting By Shruti Chaturvedi in Bangalore)