(Bloomberg) — Canada is calling on China to immediately release two citizens it claims were arbitrarily detained there, just days after the arrest of a high-profile Chinese businesswoman.

Ottawa is working to secure the pair’s release and is concerned about the “worrying precedent” the detentions set, Canada’s Foreign Affairs Minister Chrystia Freeland said Saturday on a conference call with reporters.

Michael Kovrig, a diplomat on leave from his post in Hong Kong, and Michael Spavor, an entrepreneur who helped organize tourist trips to North Korea, were seized nine days after Huawei’s Meng was taken into custody. Meng’s now out on bail pending an extradition hearing.

“Canada expects the immediate release of these two Canadians,” Freeland said, noting Chinese officials have not publicly connected the Huawei arrest and the detention of the two citizens. “My key objective here, and the Prime Minister’s key objective, is to have Mr. Kovrig and Mr. Spavor released.”

The two men were detained in China, Canada’s second-largest trading partner, shortly after the arrest of Huawei Technologies Co. Chief Financial Officer Meng Wanzhou in Vancouver at the request of U.S. authorities earlier this month.

A third Canadian is being held in China, though Canadian officials have said they see no reason to believe there’s a connection to the earlier arrests.

Kovrig’s being held at a secret detention facility where he’s questioned three times a day and unable to turn off the light, according to a person familiar with his confinement who asked not to be identified. He’s been allowed one 30-minute visit by Canadian Ambassador John McCallum in Beijing, in which he appeared stressed but unharmed, the person said.

Prime Minister Justin Trudeau is “deeply engaged” in the issue, as is the rest of the government, Freeland said. Ottawa’s working hard on a “number of fronts,” including consulting with allies to underscore the depth of its concern, she said.

Detention of foreign nationals should be guided by rule of law, not politics, she said. Canada is abiding by its extradition treaty commitments, with full due process, in its arrest of Meng, she added.

“This has not been a political decision by Canada,” Freeland said. “This is about the rule of law.”

Get The Brief. Sign up to receive the top stories you need to know right now. Please enter a valid email address. Sign Up Now Check the box if you do not wish to receive promotional offers via email from TIME. You can unsubscribe at any time. By signing up you are agreeing to our Terms of Use and Privacy Policy . This site is protected by reCAPTCHA and the Google Privacy Policy and Terms of Service apply. Thank you! For your security, we've sent a confirmation email to the address you entered. Click the link to confirm your subscription and begin receiving our newsletters. If you don't get the confirmation within 10 minutes, please check your spam folder.

Contact us at letters@time.com.