China has said it will stage military exercises in the East China Sea near Taiwan this week, with relations tense between Beijing and the self-ruled island.
This will be the third set of drills in a month and comes after the recent US approvals of arms sales worth billions to Taiwan, including F-16 fighter jets.
Ties between Beijing and Taipei have plummeted since President Tsai Ing-wen came to power in 2016 because her party refuses to recognise the idea that Taiwan is part of "One China".
As punishment, Beijing has cut official communications, ramped up military exercises, poached diplomatic allies and increased economic pressure on the island.
Beijing sees Taiwan as part of its territory awaiting unification, even though the two sides have been ruled separately since the end of a civil war in 1949.
Ships will be prohibited from entering the waters off the coast of China's eastern Zhejiang province for 48 hours starting 6:00 pm (1000 GMT) on Tuesday because of the military exercises, the Zhejiang Maritime Safety Administration said in a brief notice on Monday.
It did not offer details on the scale of the exercises or which military units were involved.
State-backed newspaper Global Times called it a "live-fire drill".
The People's Liberation Army held two large military drills close to the Taiwan Strait in late July.
"The idea is to better prepare for conflict but also deter... Taiwan (from) going down the path of independence or, failing that, a US intervention if conflict breaks out between China and Taiwan," said Adam Ni, China researcher at Macquarie University in Sydney.
The series of drills follows a defence white paper published in July, in which the Chinese military warned about a growing challenge from pro-independence forces in Taiwan.