Canada's foreign ministry says a third Canadian national has been detained in China. <br />The move threatens to escalate an already tense diplomatic feud between the two nations, which came after the arrest of a Chinese executive in Canada earlier his month.<br />Since then two Canadians have been detained in China, but Ottawa officials say they don't believe the third arrest is linked to those arrests.<br />Canadian Prime Minister Justin Trudeau expressed concern, saying more information is being collected. <br />Beijing's foreign ministry said it was unaware of the third arrest. <br />
