Canada said on Thursday that 13 of its citizens have been detained in China since Huawei Technologies Co Chief Financial Officer Meng Wanzhou was arrested last month in Vancouver at the request of the United States.

"At least" eight of those 13 had since been released, the Canadian government said in a statement, without disclosing what charges if any have been laid.

Prior to Thursday's statement, detention of only three Canadian citizens had been publicly disclosed. Diplomatic tension between Canada and China has intensified since Meng's arrest on Dec 1.

The Canadian government has said several times it sees no explicit link between the arrest of Meng, the daughter of Huawei's founder, and the detentions of Canadian citizens.

But Beijing-based Western diplomats and former Canadian diplomats have said they believe the detentions were a "tit-for-tat" reprisal by China.

Meng was released on a C$10 million ($7.4 million) bail on Dec 11 and is living in one of her two multi-million-dollar Vancouver homes as she fights extradition to the United States. The 46-year-old executive must wear an ankle monitor and stay at home from 11 pm to 6 am.

The 13 Canadians detained include Michael Kovrig, Michael Spavor and Sarah McIver, a Canadian government official who declined to be identified, said on Thursday.

McIver, a teacher, has since been released and returned to Canada. Kovrig and Spavor remain in custody. Canadian consular officials saw them once each in mid-December.

Overall, there are about 200 Canadians who have been detained in China for a variety of alleged infractions who continue to face on-going legal proceedings. "This number has remained relatively stable," the official said.

In comparison, there are almost 900 Canadians in a similar situation in the United States, the official added.

Chinese Foreign Ministry spokesman Lu Kang did not provide details about the other detained Canadians at a news briefing in Beijing on Friday, but said that China was ruled by law and it protected the legal rights of foreigners.

The Chinese government has not drawn a direct link between the detention of any Canadian and Meng's arrest. It has demanded that Canada free Meng and threatened unspecified consequences if it does not.