BEIJING (AP) — China’s airline regulator has warned travelers to expect flight delays at 12 airports through mid-August, and an airport employee said military exercises are the reason.

The Civil Aviation Administration of China said airports affected include the major cities of Shanghai, Nanjing, Hangzhou, Zhengzhou and Qingdao, China Central Television said Tuesday on its website.

Disruptions began July 20 and are due to last through Aug. 15, according to CCTV. It said the delays were due to unspecified exercises but gave no other details.

An airport employee reached by phone in one of the cities, Lianyungang, said the delays were due to military exercises.

“We got a verbal notice from our supervisor that flights may be delayed at airports in east China due to military exercises,” said the man, who refused to give his name.

On July 14, more than 100 flights at Shanghai’s two international airports were delayed or cancelled. The government gave no explanation, prompting rumors the disruption was due to military exercises.

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