Protesters from Greenpeace, the environmental lobby group, stormed the International Petroleum Exchange in London today, disrupting trade at one of the world's most important energy markets.

“It’s to mark the adoption of the Kyoto treaty. About 35 Greenpeace volunteers have gone on to the trading floor at 2pm when trade switched over from electronic to day trade,” a Greenpeace spokesperson said.

Police closed off a section of the Highway, where the IPE is located, a key route into the City of London by Tower Bridge, causing near gridlock for traffic in east London. The switch to day trading was delayed as a result of the protest.

“The idea is to disrupt trade. Several of the volunteers have attached distress alarms to helium balloons,” the Greenpeace spokesperson said.

The IPE refused to comment, but one source housed in the same office building said that security has requested that no one leave the building and that protesters are now on the roof.

Oil trading on the exchange was set to re-open at 3.10pm, according to traders at Man Energy.

The IPE trades contracts for North Sea Brent crude oil, which has rocketed in value over the past year as world demand has increased.

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