Beijing, China - Four Canadian citizens were executed by Chinese authorities over the last weeks on suspected drug offenses, despite condemnation and pleas from Ottawa.

Canada has since updated its travel advice for China based on "the risk of arbitrary enforcement of local laws."

Canadian foreign minister Mélanie Joly told reporters that while Ottawa had campaigned for leniency, Beijing moved forward with the executions, which were handed down on the basis of drug smuggling charges.

"There are four Canadians that have been executed, and therefore we are strongly condemning what happened," Joly said.

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"We will continue to engage with China as we will continue to not only strongly condemn, but also ask for leniency for other Canadians that are facing similar situations," she said.

Joly declined to go into detail about the individuals and their cases, as the families have asked that details be kept private. She confirmed that that Canadian authorities were in close contact with the families.

China justified the executions as being "in accordance with the law," and brushed aside Canada's condemnation of the death penalty.

According to foreign ministry spokesperson Mao Ning, Beijing will always treat defendants of varying nationalities "without discrimination" and handle cases "fairly in strict accordance with the law."

"Drug-related crime is a severe crime recognized worldwide as extremely harmful to the society," China's embassy said in a statement sent to the press.

"China always imposes severe penalties on drug-related crimes and maintains a 'zero tolerance' attitude towards the drug problem."