Hundreds of people gathered in a park in the Canadian capital Ottawa to mark the one thousandth day since China arrested two Canadians on spying charges, a case that has soured diplomatic ties between Ottawa and Beijing.
The protesters demanded the release of businessman Michael Spavor and former diplomat Michael Kovrig.
Many carried banners and wore white shirts that read 'Bring Them Home'.
Canada's Foreign Affairs Minister also attended the rally, and said that years had been 'cruelly stolen' from the men and their families.
The so-called 'Two Michaels' were detained in China in 2018, just days after the arrest of Meng Wanzhou on a warrant from the United States.
She's the Chief Financial Officer of Chinese tech giant Huawei.
She was charged with misleading global banking company HSBC on Huawei's dealings with Iran, which could have led the bank to breach U.S. sanctions.
Meng has repeatedly denied this and has been fighting her extradition from under house arrest in Vancouver.
She now awaits a verdict after hearings for her extradition wrapped up last month.
Beijing has denied that Meng and the Michaels were related, but it also warned of unspecified consequences unless she was released.
Last month, a Chinese court sentenced Spavor to 11 years in prison for espionage, while Kovrig's verdict has yet to be announced.
Since Meng's arrest, China has also sentenced four Canadians to death over drug charges.