Russia has dropped piracy charges against 30 people involved in a Greenpeace protest over Arctic oil drilling, replacing them with lesser charges, the Itar-Tass news agency reported on Wednesday, citing federal investigators.

Investigative Committee spokesman Vladimir Markin said the charges against activists who protested at an oil platform in the Pechora Sea last month had been changed from piracy, which carries a maximum jail sentence of 12 years, to hooliganism, which has a maximum sentence of seven years, Itar-Tass reported.

'We will contest the trumped-up charge of hooliganism as strongly as we contested the piracy allegations.'- Vladimir Chuprov, Greenpeace Russia

Greenpeace said the lesser charge is still "wildly disproportionate" to the activists' actions.

"We will contest the trumped-up charge of hooliganism as strongly as we contested the piracy allegations," said Vladimir 
Chuprov of Greenpeace Russia in a statement. "They are both fantasy charges that bear no relation to reality."

The Investigative Committee warned that it could charge the activists with additional offences, including violence against authorities. That charge is punishable by up to 10 years in prison.

But Greenpeace dismissed the allegation that its members used force against officials, pointing out its organization's 42-year history of peaceful protest.

"They arrived at that oil rig in a ship painted with a dove and a rainbow," Chuprov said.

2 Canadians among those arrested

The activists were arrested Sept. 19 along with two journalists when the Russian coast guard stormed Greenpeace’s Arctic Sunrise ship, which was near a drilling rig in the Prirazlomnaya oil field owned by the Russian state oil company Gazprom

Two Canadians — Alexandre Paul of Montreal and Paul Ruzycki of Port Colborne, Ont. — are among those being held in the northern port city Murmansk. The group includes 28 activists and two journalists from 18 different countries: Argentina, Australia, Brazil, Canada, the Czech Republic, Denmark, Britain, Finland, France, Italy, the Netherlands, New Zealand, Poland, Russia, Sweden, Turkey, Ukraine and the United States.

Last week, 11 Nobel Peace Prize laureates, including South African anti-apartheid campaigner Desmond Tutu, released an open letter calling on Russian President Vladimir Putin to release the demonstrators.

With files from The Associated Press