Activists staged sit-in protest inside the main entrance to BP Plc’s (NYSE: BP) Houston headquarters April 15 ahead of the five-year anniversary of the Deepwater Horizon spill, a press release from Rainforest Action Network (RAN) said.

Six people have been arrested, the group said.

Under a four-story glass atrium in BP’s central lobby, protesters said they unfurled a 10-foot banner that reads “NEVER AGAIN: No Sacrifice Zones” as well as other banners and signs reading “Extreme Energy Out Of Our Communities” and “No Kill, No Spill: Keep It In The Ground.”

The protest is the first of several demonstrations planned across the Gulf South leading up to the April 20 oil spill anniversary. This includes planned protests on April 16 outside BP’s annual shareholder meeting in London.

In April 2010, the Deepwater Horizon disaster killed 11 workers and released at least 3.19 million barrels of oil into the Gulf of Mexico. The Smithsonian Museum of Natural History said the spill is recognized as the worst in U.S. history.

In March, BP said that in the five years since the spill scientific data and studies are showing that the Gulf environment is returning to its baseline condition.

The Smithsonian says the Gulf is still not oil free.

The company has spent $14 billion and employed about 100,000 workers to respond to the spill and clean the shoreline. BP's report noted that the National Research Council estimates that every year, natural seeps release 560,000 to 1.4 million barrels of oil into the Gulf – the equivalent of up to nearly six Exxon Valdez spills.

Rainforest Action Network points to the ongoing crisis of the BP oil disaster as evidence for the urgent need for fundamental changes to the existing federal system of fossil fuel leasing. In response to disasters such as the Deepwater Horizon, the Obama administration has recently implemented regulatory changes to offshore oil drilling.

Rainforest Action Network is based in San Francisco.

Offshore