TAIPEI, Taiwan — Tens of thousands of Taiwanese working in China are at risk of being unable to return home for the Lunar New Year in mid-February as a result of an escalating battle over airspace in the Taiwan Strait.

On Tuesday, the Chinese airlines China Eastern Airlines and Xiamen Air announced that they had canceled 176 flights intended to meet added demand during the holiday since they had yet to receive approval from Taiwan’s Civil Aeronautics Administration.

The agency said on Jan. 19 that it was denying the airlines permission for the flights because they were flying sensitive new routes in the Taiwan Strait that China began using without consulting Taiwan’s government. The move has been viewed in Taiwan as a show of disrespect, one that could heighten the risk of a dangerous incident and potentially provoke a crisis in the increasingly tense cross-strait relationship.

The new passenger routes come close to airspace used by Taiwanese airliners and military planes at a time when Chinese military drills encroaching on Taiwan’s airspace have become increasingly common.