TAIPEI (Reuters) - Taiwan's defence ministry accused China on Saturday of threatening aviation safety and waging psychological warfare on the island's people with a recent spate of balloons spotted near or over the island, days before key Taiwanese elections.

The potential for China to use balloons for spying became a global issue in February when the United States shot down what it said was a Chinese surveillance balloon. China said the balloon was a civilian craft that accidentally drifted astray.

Taiwan is on high alert for Chinese military and political activity ahead of the Jan. 13 presidential and parliamentary elections. It says China is exerting military and economic pressure in an attempt to interfere in the elections.

China views the island as its own territory, a claim Taiwan's government rejects.

Since last month Taiwan's defence ministry has reported several instances of Chinese balloons flying over the sensitive Taiwan Strait. It said this week some balloons had flown over Taiwan island near major air bases.

In a statement on Saturday, the ministry said the balloons were a "serious threat" to international aviation safety given their flight paths.

"We also express our condemnation of the Chinese communists' disregard for aviation safety and its disregard for the safety of passengers on cross-Taiwan Strait and international flights," it said.

The ministry said its analysis was that the balloons were part of China's "grey zone" tactics against Taiwan "in an attempt to use cognitive warfare to affect the morale of our people".

Calls seeking comment to China's defence ministry, Taiwan Affairs Office and civil aviation administration were not answered on Saturday outside of work hours.

China's defence ministry last week declined to comment on the balloons at a monthly news conference.

Taiwan says Chinese balloons threaten aviation safety