China's air force has released a propaganda film dubbed into Hokkien, a language strongly identified with Taiwan's pro-independence movement, showing bomber aircraft which have been involved in flying patrols around the self-ruled island.

China has been issuing increasingly stern warnings for democratic Taiwan to toe the line, including a stepped up military presence and flying bomber patrols around the island as it seeks to curb what Beijing believes are efforts to push for the island's formal independence.

China claims Taiwan as its sacred territory, and the issue of Taiwan is extremely sensitive in Beijing.