March 15 (UPI) — Taiwan’s defense ministry on Sunday said that more than two dozen Chinese military aircraft and several naval vessels were detected near the island, which comes after a period with relatively few such incursions.

After decreased presence of Chinese incursions into the island’s air defense identification zone (ADIZ) during the last two weeks, China sent 26 aircraft that were spotted around the island – 16 of which violated the ADIZ – and seven naval vessels sailed toward it, The Independent and The Wall Street Journal reported.

China considers Taiwan to be its territory. On a regular basis, it sends military aircraft and naval vessels toward the island, but during 10 of the last 16 days — from Feb. 27 to March 5 and March 7 to 10 — no flights near the island were reported.

On the other days, there were as few as two flights detected.

Taiwan regards the incursions into its airspace and waters as routine harassment, for the most part, but China also has held military exercises close to what Taiwan considers its territory and has threatened to take the island by force if it deems it necessary.

Wellington Koo, Taiwan’s defense minister has said that although there has been a noticeable decrease in aircraft nearing or crossing the ADIZ, the island nation’s military planned to stay on guard.

“We cannot rely on a single indicator like the absence of aircraft,” Koo told The Journal, because naval vessels still circle the island daily.

Analysts have suggested that the decrease in incursions is timed to a meeting of the Chinese legislature, which has happened previously, or be part of a diplomatic or strategic play before U.S. President Donald Trump and Chinese President Xi Jinping meet in Beijing at the end of the month.