Some 30 protesters also displayed a banner saying "We are stopping dinosaur technology" and dumped three tonnes of coal in front of the company's offices.

The steel dinosaur weighed one tonne and was five metres high (16 feet), the organisation said.

Sweden-based Vattenfall plans to build a 1,600-megawatt coal-fired plant in Hamburg at a cost of two billion euros (three billion dollars).

Emissions from coal-fired plants are believed to be one of the main contributors to global warming.