DENVER — An oil company is reporting three more spills from storage tanks in a Colorado oil field swamped by floodwaters.

Friday's disclosure from Texas-based Anadarko Petroleum Corp. came as cleanup efforts remained stalled due to continued high waters.

The latest reported spills include 2,400 gallons from a toppled storage tank and two others of unknown volume, also from damaged storage tanks.

That brought the known volume of oil released to date from massive flooding along Colorado's Front Range to an estimated 21,200 gallons. That's about 500 barrels.

At least four of the five known spills drained into the South Platte River or a tributary.

Regulators caution that more oil releases are likely to be found in coming days.

State officials say much of the spilled oil has been carried at least some distance by floodwaters, which could further hamper cleanup efforts.