US sues BP over oil disaster

The US is suing BP and eight other firms for allegedly violating federal safety regulations in connection with the Gulf of Mexico oil spill.

The lawsuit asks that they be held liable without limitation for all clean-up and damage costs.

The Deepwater Horizon drilling rig explosion in April killed 11 workers and spilled millions of barrels of oil over several months.

The oil leak became the worst environmental disaster in US history.

The lawsuit charges the companies under the US Clean Water Act and Oil Pollution Act.

US Attorney General Eric Holder said the complaint alleges that "violations of safety and operational regulations" caused the 20 April explosion.

The companies targeted in the lawsuit are BP Exploration and Production Inc, Anadarko Exploration & Production LP, Anadarko Petroleum Corporation, MOEX Offshore 2007 LLC, Triton Asset Leasing GMBH, Transocean Holdings LLC, Transocean Offshore Deepwater Drilling Inc, Transocean Deepwater Inc and QBE Underwriting Ltd/Lloyd's Syndicate 1036 - BP's insurer.

The key accusations are:

* Failing to take necessary precautions to keep the Macondo Well under control in the period leading up to the April 20th explosion
* Failing to use the best available and safest drilling technology to monitor the well's conditions
* Failing to maintain continuous surveillance
* Failing to use and maintain equipment and material that were available and necessary to ensure the safety and protection of personnel, equipment, natural resources, and the environment

Halliburton, the company that cemented the Macondo Well, and Cameron International, which provided equipment for the well, were not targeted in the lawsuit.

But the Justice Department said on Wednesday that the investigation into the oil spill was ongoing and more defendants and charges could be added to the suit.

"We intend to prove that these defendants are responsible for government removal costs, economic losses and environmental damages without limitation," Mr Holder said.

"As investigations continue, we will not hesitate to take whatever steps necessary to hold accountable those responsible for this spill," Mr Holder added.

Mr Holder did not specify a timetable in the lawsuit, instead saying the US would move as quickly as possible in the matter.

Eleven workers on the Deepwater Horizon drilling rig were killed by an explosion which followed, and hundreds of miles of coast were polluted before it was stemmed in July.