Two military helicopters will enter the no-fly zone above the city to enact a scenario that the city government has been attacked and officials have been kidnapped.

While urging citizens not to panic over the exercise scheduled for September 22, Taipei Mayor Ma Ying-jeou said: "We have to prepare for the worst although it might not happen."

The drill will see Taipei's city government working with the defense ministry "to review how the capital could maintain its command should it be attacked by terrorists," an official told AFP.

Military engineer troops will also show their ability to rebuild bridges "destroyed" in the mock attacks, the official said.

However, he dismissed reports that the drill would involve the world's tallest skyscraper, the Taipei 101 building, saying construction of the 508-meter tower had not been completed.

Despite an official insistence that the drill is not a preparation for war, it comes at a sensitive moment in the increasingly tense relationship between Taipei and Beijing.

Taiwan has repeatedly warned of a possible blitz on Taiwan's Presidential Office and other key government posts by the People's Liberation Army, modelled on the swift US military action to depose Saddam Hussein.

China, which has some 600 missiles aimed at the island, has itself been staging large military exercises on Dongshan island, 150 nautical miles west of Taiwan, to prepare for any conflict.

Taiwan has staged a string of military war games, although a major exercise scheduled for Wednesday has been put off until next month because of Typhoon Aere.

Since pro-independence President Chen Shui-bian was re-elected in March, Beijing has stressed its long-standing vow to take Taiwan by force should the island try to declare a formal split.

WAR.WIRE