Saudi Arabia said Monday it was expelling the Canadian ambassador and had recalled its envoy while freezing all new trade, in protest at Ottawa's vigorous calls for the release of jailed activists.

The kingdom gave the Canadian ambassador 24 hours to leave the country, in an abrupt rupture of relations over what it slammed as "interference" in its internal affairs.

The move, which underscores a newly aggressive foreign policy led by Crown Prince Mohammed bin Salman, comes after Canada demanded the immediate release of human rights campaigners swept up in a new crackdown.

"The Canadian position is an overt and blatant interference in the internal affairs of the kingdom of Saudi Arabia," the Saudi foreign ministry tweeted.

"The kingdom announces that it is recalling its ambassador to Canada for consultation. We consider the Canadian ambassador to the kingdom persona non grata and order him to leave within the next 24 hours."

Statement | The KSA announces the freezing of all new trade and investment transactions between the KSA and Canada. The KSA reserves its right to take further action.— Foreign Ministry (@KSAmofaEN) August 5, 2018

The ministry also announced "the freezing of all new trade and investment transactions with Canada while retaining its right to take further action".

Canada last week said it was "gravely concerned" over a new wave of arrests of women and human rights campaigners in the kingdom, including award-winning gender rights activist Samar Badawi.

"We urge the Saudi authorities to immediately release them and all other peaceful #humanrights activists," the foreign ministry tweeted on Friday.

'Unprecedented crackdown'

Samar was arrested along with fellow campaigner Nassima al-Sadah last week, the latest victims of what Human Rights Watch called an "unprecedented government crackdown on the women's rights movement".

Samar is a vocal campaigner for blogger Raif Badawi, her brother who was arrested in 2012 and sentenced to 1,000 lashes and 10 years in jail for "insulting Islam" in a case that sparked an international outcry.

The latest arrests come weeks after more than a dozen women's right campaigners were detained and accused of undermining national security and collaborating with enemies of the state. Some have since been released.

The Saudi foreign ministry slammed the Canadian statement, signalling its growing irritation over Western criticism of the kingdom's poor human rights record.

"Using the phrase 'immediately release' in the Canadian statement is very unfortunate, reprehensible, and unacceptable in relations between states," the ministry tweeted.

#Statement | Throughout its long history, the Kingdom of Saudi Arabia has never accepted any interference in its domestic affairs by, or orders from any country. pic.twitter.com/sUrj7XIqTV— Foreign Ministry (@KSAmofaEN) August 6, 2018

Prince Mohammed, heir to the region's most powerful throne, has introduced a string of reforms such as lifting a decades-long ban on women drivers in a bid to overhaul the kingdom's austere image as it prepares for a post-oil era.

But the 32-year-old has simultaneously pursued a hawkish foreign policy -- including leading a blockade of neighbouring Qatar and a bombing campaign against Iran-backed Huthi rebels in Yemen -- while cracking down on dissent at home.

'Serious concern'

"The rupture in Saudi diplomatic relations with Canada reinforces how the 'new' Saudi Arabia that Mohammed bin Salman is putting together is in no mood to tolerate any form of criticism of its handling of domestic affairs," said Kristian Ulrichsen, a fellow at Rice University's Baker Institute in the United States.

In April, Canadian Prime Minister Justin Trudeau expressed his "serious concern" over the continued jailing of Badawi to Saudi King Salman.

Badawi's wife Ensaf Haidar has been granted asylum by Canada, where she is raising their three children now aged 14, 13 and 10 as a single mother.

Riyadh's expulsion of the Canadian ambassador was meant to send a strong message to other critical Western governments, observers say.

"Canada is easier to cut ties with than the rest," Bessma Momani, a professor at Canada's University of Waterloo, told AFP.

"There isn't a strong bilateral trade relationship and poking the Trudeau government likely resonates with Saudi's hawkish regional allies. At jeopardy, are the tens of thousands of Saudi students in Canada."