CALIFORNIA (REUTERS) - Beaches in a southern California city that were shut because of an oil spill last week are set to reopen on Monday (Oct 11) morning, the authorities said in a statement.

City and state beaches of Huntington Beach city will reopen as water quality testing showed no detectable amounts of oil associated toxins in ocean water, officials from the city and California State Parks said.

Last week, some 3,000 barrels of crude oil spilled into the Pacific Ocean, killing wildlife, soiling the coastline and forcing officials to close beaches in the cities of Huntington Beach, Newport Beach and Laguna Beach in Orange County, just south of Los Angeles.

The US Coast Guard is investigating a vessel in Oakland, focusing on the possibility that a ship's anchor struck a pipeline and caused the oil spill, the Los Angeles Times reported.

The authorities will test the water for at least the next two weeks to monitor for toxins, according to the statement.

Huntington Beach, which advertises itself as Surf City USA, is one of the rare places in Southern California where oil platforms are visible from the shore.