OTTAWA (AFP) - Canada Wednesday (July 1) warned its citizens in Hong Kong that they faced a higher risk of arbitrary detention and extradition to mainland China after Beijing imposed a new security law on the city.

"National security legislation for Hong Kong came into effect on July 1, 2020," the Canadian government wrote in an updated travel advisory.

"You may be at increased risk of arbitrary detention on national security grounds and possible extradition to mainland China."

The warning illustrates heightened concerns some Western governments have for citizens after China imposed a law on Hong Kong outlawing subversion, secession, terrorism and colluding with foreign forces.

Relations between Canada and China are at their lowest in years following a row over the fate of arrested nationals.

Canadian former diplomat Michael Kovrig and businessman Michael Spavor were both detained for nine days after Canada arrested Chinese Huawei executive Meng Wanzhou following an American extradition request.

The two men have been held largely incommunicado since December 2018 and slapped with spy charges weeks after a Canadian judge ruled that extradition proceedings against Meng will go ahead.

Beijing has made little secret of the fact that the two men's fates are tied up with Meng's.