OTTAWA -- The Conservative government has announced further economic sanctions against organizations in Russia -- including a pro-Putin biker gang known as the Night Wolves.

Prime Minister Stephen Harper says there must be ongoing consequences for Russia's aggression in Crimea.

The latest sanctions target four energy giants, including gas producers Gazprom, Gazprom Neft, Surgutneftegas and Transneft, a pipeline company.

Three Eurasian Youth Union leaders have also been hit with travel bans, joining a list that already includes the head of the Night Wolves.

The government has also imposed a ban on imports and exports from Crimea.

Harper says further steps were taken in co-ordination with international partners.

Canada continues to call on Russia to implement commitments outlined under the Minsk agreements.

Last August, Russia announced a year-long ban on certain argricultural imports from countries, including Canada, that imposed sanctions.