OTTAWA -- The federal government is decrying a mass execution in Saudi Arabia which killed 47 people, including a prominent Saudi Shiite cleric.

In a statement issued on Sunday, Foreign Affairs Minister Stephane Dion says Canada is calling on the Saudi Arabian government to "protect human rights, respect peaceful expressions of dissent and ensure fairness in judicial proceedings."

Dion says Canada is particularly concerned that the country's execution of Sheikh Nimr al-Nimr could "further inflame" sectarian tensions in the region.

His comments came as Saudi Arabia announced Sunday that it was severing diplomatic relations with Iran amid escalating tensions over the cleric's execution.

Iran's supreme leader, Ayatollah Ali Khamenei, warned Saudi Arabia of "divine revenge" over al-Nimr's execution, while Riyadh accused Tehran of supporting "terrorism."

Al-Nimr's death also drew protests from Shiites around the world, who backed his call for reform and wider political freedom for their sect.

Dion says Canada is urging authorities and leaders in Saudi Arabia and Iran to work to defuse tensions and promote reconciliation.

Al-Nimr was a central figure in Arab Spring-inspired protests by Saudi Arabia's Shiite minority until his arrest in 2012. He was convicted of terrorism charges but denied advocating violence.

The mass execution which killed him was the largest carried out by Saudi Arabia in three and a half decades.

It exposed the sectarian divisions gripping the region and also illustrated the kingdom's new aggressiveness under King Salman.

During his reign, Saudi Arabia has led a coalition fighting Shiite rebels in Yemen and staunchly opposed regional Shiite power Iran, even as Tehran struck a nuclear deal with world powers.

With files from the Associated Press.