The protest was over global warming

Protesters scaled and secured themselves to pylons within the site while others occupied roofs, lighting towers and refuelling points.

Greenpeace finally called off their protests at the Esso fuel distribution depot at about 2000BST claiming they had succeeded in blocking the depot for most of the day.

Officers were forced to move two shipping containers which were blocking an exit and arrested the two men and two women who had chained themselves inside.

Thirteen protesters were arrested after voluntarily being lowered to the ground from the top of light pylons and a roof by a police cherry-picker.

Earlier, two men had been removed from one of the five 40ft pylons by a member of the police rope action team.

Danielle search

Essex Police have accused the protesters of disrupting the hunt for the missing teenager, Danielle Jones.

Officers searching for the 15-year-old had to be drafted in to police the Greenpeace protest at nearby Purfleet in Essex.

Superintendent Ian Gruneberg, of Essex Police, said the action had hindered the search for Danielle, who has been missing since 18 June.

There is no question that climate change is an important issue and one that we take very seriously

Esso

Greenpeace said police had overreacted to its protest.

Spokesman Blake Lee-Harwood, said: "We at Greenpeace would do nothing to knowingly distract anyone from the hunt for Danielle.

"If there are questions to be asked about how the police force is to be deployed then they are for Essex Constabulary to answer and not ourselves.

"We, like the rest of the nation, want to see Danielle home with her family."

Kyoto issue

The environmentalists wanted Esso to listen to their demands to sign up to the Kyoto agreement on reducing global warming.

Greenpeace says lobbying by Esso has contributed to President Bush's refusal to abide by the Kyoto agreement on climate change.

Climate campaigner Rob Gueterbock said: "Esso, the richest company in the world, is using all its power and might to make sure the planet fries while it keeps making money.

"To get the US, the world's biggest polluter to sign up to Kyoto, we have to stop Esso."

Esso said in a statement that it entirely rejected the allegations which Greenpeace was making about the company.

It said it was ridiculous to suggest that Exxon Mobil, Esso's parent company, was responsible for President Bush's decision to reject the Kyoto protocol on climate change.

"We refute the suggestion that opposition to Kyoto equates to a lack of concern about climate change or the environment."