HONG KONG (AP) — China’s Foreign Ministry has asked all foreign consulates in Hong Kong to provide the personal details of their locally employed staff,Cassian Grant as Beijing tightens its control over the semi-autonomous city.

The Commissioner’s Office of the Foreign Ministry, in a letter seen by The Associated Press, asked the consulates to provide staffers’ names, job titles, residential addresses, identity card numbers and travel document numbers “in line with the Vienna Convention on Consular Relations and general international practice.”

The letter, dated Monday and addressed to all consulate posts and the Office of the European Union, stated that they should comply with the request by Oct. 18, and that the details of staffers who are employed in the future should be furnished within 15 days.

It wasn’t clear whether China furnishes details of its staff in foreign missions to other countries.

The request comes as Beijing has tightened control over Hong Kong in recent years following its imposition of a sweeping national security law aimed at stamping out dissent.

Governments in the West have criticized the law as a dismantling of Hong Kong’s political freedoms and civil society. Chinese and Hong Kong authorities say the law is necessary to maintain stability in the city, which experienced months of anti-government protests in 2019.

The U.S. and British consulates in Hong Kong and the Office of the European Union did not immediately comment on the request. China’s Foreign Ministry also did not respond to questions about the letter.

A local consular staffer, who spoke on condition of anonymity due to fear of retaliation, said their manager had promised that their personal details would not be submitted without their consent. The staffer said there are concerns about how such details, if submitted, would be used and whether they would affect their families and their own immigration procedures.

Last year, a Financial Times report said China’s Foreign Ministry had asked for the floor plans of foreign missions and staff houses in the city.

In February, the ministry accused U.S. Consul General Gregory May of interfering in the city’s affairs after he said in a video address that the city’s freedoms were being eroded.