Saudi Arabia’s state airline has suspended its direct flight service to Toronto, in an escalation of a diplomatic row between the two nations sparked by Canada’s call for the release of human rights activists detained in the kingdom reports The Week

The move follows Saudi Arabia’s freezing of all new investment and trade with Canada, the expulsion of the Canadian ambassador and the recall of the Saudi ambassador.

Canada’s foreign minister, Chrystia Freeland, responded to the moves on Twitter, saying: “Canada will always stand up for human rights in Canada and around the world, and women’s rights are human rights.”

The row between the two nations began on Friday, August 3 when Canada “expressed concern over the arrests of activists in Saudi Arabia, including prominent women’s rights campaigner Samar Badawi”, The Guardian reports.

Riyadh responded to Canada’s remarks, saying: “The kingdom of Saudi Arabia... will not accept interference in its internal affairs or imposed diktats from any country.”

The BBC reports that “at least 15 human rights defenders and women's rights activists critical of the Saudi government” have been detained since 15 May, and the whereabouts of several of those detained are currently unknown.