HONG KONG — The Hong Kong authorities said Tuesday that they were considering banning a political party that advocates the city’s independence from China, an aggressive move against separatist sentiments that added to concerns about growing restrictions on political freedom in the territory.

The two-year-old political party targeted by the government, the Hong Kong National Party, is small, claiming at most a few dozen members and no elected lawmakers.

The government has previously placed restrictions on the party, barring its head, Chan Ho-tin, from running for office two years ago.

John Lee, the Hong Kong security secretary, said on Tuesday that the government was reviewing whether to ban the party under the territory’s societies ordinance, which authorizes the prohibition of groups for reasons such as national security, public safety and public order.