Authorities in China have detained a man they said is an independence activist.

The move comes after US House Speaker Nancy Pelosi visited Taiwan.

Yang Zhiyuan, 32 – said to be a long-time supporter of independence in Taiwan, according to Chinese state media – was detained in the port city of Wenzhou, in eastern China’s Zhejiang province and could face the death penalty.

He is being held on charges of suspicion of endangering national security.

The charges come as furious China takes revenge measures in response to Pelosi’s high-profile visit to the disputed territory.

Beijing says Taiwan is a rebel breakaway region of China, while Taiwan says it is an independent state.

China has accused Yang Zhiyuan of being a Taiwanese separatist and has held him on suspicion of endangering national security, according to Chinese state media.

The 32-year-old has also reportedly been accused of being a long-time defender of Taiwanese independence and of being the founder of a Taiwanese Nationalist Party, said state-controlled media.

If convicted, he could reportedly face the death penalty.

Beijing has reacted with fury at Pelosi’s trip to Taipei, initiating a series of aggressive military exercises near the island and imposing economic sanctions on Taiwanese businesses and people.