Taiwan kicked off its biggest annual war game Monday, testing its ability to defend of the capital Taipei against a Chinese attack and ward off a blockade of its main naval base.

Thousands of reservists reported for the five-day drill, which is codenamed "Han Kuang (Han Glory) No 28".

Hundreds of troops were also deployed outside Taipei as the military simulated a Chinese landing on the shores of the Tamshui River, which flows through the capital, defence ministry officials said.

In the south, the navy mobilised a fleet of mine-sweeping vessels and helicopters for a scenario in which Tsoying, the island's major naval base, is the target of a Chinese blockade.

Ties between Taiwan and its former rival China have improved drastically since Ma Ying-jeou of the China-friendly Kuomintang party came to power in 2008 promising to boost trade and tourism links.

But China still claims sovereignty over Taiwan, which has governed itself since 1949, and has vowed to get it back -- by force if necessary -- even though the island has ruled itself for more than 60 years.