The Faroese government said in a statement that it had barred a Sea Shepherd ship, the Bob Barker, "with a basis in immigration legislation and in the interests of maintaining law and order".
"In recent weeks, anti-whaling activists representing the animal rights group Sea Shepherd have deliberately attempted to disrupt the legal and regulated activity of driving and killing pilot whales for food in the Faroe Islands, leading to the arrest, prosecution and expulsion from the Faroe Islands of a number of these activists," the statement added.
Tensions have been high between those who defend the traditional whale hunt, and animal rights activists who say the practice causes unnecessary bloodshed.
During the hunt, the whales are led to a bay or the mouth of a fjord before being killed by hand.
The Faroe Islands say that the number of animals killed is small compared to the population. About 800 whales are killed per year out of a population of more than 750,000.
Residents have traditionally eaten the whale meat, but more recently health authorities have advised to eat it only once a month, and for pregnant women to avoid it all together, because of the high concentration of heavy metals and dioxins.
The court handed down sentences ranging from a fine of 5,000 kroner (670 euros, $735) or eight days in prison, to 35,000 kroner or 14 days in prison.
Contacted by AFP, the government and the police did not give the nationalities of the activists on the Bob Barker.
No Sea Shepherd spokesperson was available for comment Monday.