Dozens of activists from 18 countries occupied four coal-fired power plants across Italy on Thursday, climbing smokestacks to hang banners calling on the Group of Eight summit to take the lead in fighting climate change, Greenpeace said.
Italian energy giant Enel, which owns three of the plants, said production had not been disrupted. Employees at two of the plants staged counter-demonstrations and the union for Italy's energy workers condemned the protest.
In Rome, activists from charity group Oxfam International put on masks of world leaders and dressed up as chefs, stirring a mock Earth in a pot representing the planet's rising temperature.
On the historic Spanish Steps, where environmentalists stripped half-naked and unfurled a banner calling on leaders to "Keep climate cool." Two women, a French and an American, as well as a Greek man were briefly detained by police.
The stunts came a day after anti-globalisation groups in the capital blocked roads, rail tracks, and clashed with police in violent protests against the G-8. Nearly 40 Italian and foreign activists were detained.
The ANSA news agency reported that police had taken in four Dutch citizens who were travelling to the summit area with helmets, gas masks and sticks in their car.
Several demonstrations have been scheduled in Rome and L'Aquila, the quake-shattered central Italian town that is hosting the three-day summit that opened today. Critics of the G-8 have also vowed to stage surprise protests across the country.