Global Affairs, as Canada’s foreign ministry is known, did not provide further details or say whether the case was related to the detention of 19 people earlier in the week.
Relations between China and Canada nosedived last December after Vancouver police detained Meng Wanzhou, the chief financial officer of Huawei Technologies Co , on a U.S. arrest warrant. Beijing is demanding her return.
After Meng’s arrest, China detained two Canadians, accusing them of involvement in stealing state secrets.
On Tuesday, police in Xuzhou, a city in Jiangsu province, said it had detained 19 people on drug-related charges and that 16 of them were foreigners. Yantai is about 620 km (385 miles) away from Xuzhou.
The British Embassy in Beijing said on Friday that four British nationals have been arrested in eastern China.
China’s state radio said some of the detained individuals were teachers at an English education center operated by EF Education First, a privately held Swiss firm that operates in 114 countries.