Etihad Airways canceled flights to and from Shanghai following passengers testing positive for the coronavirus on arrival there. The Abu Dhabi-based carrier will tighten already strict virus-related regulations on passengers as it continues to fly amid the pandemic.

Six passengers aboard an Aug. 3 flight from Abu Dhabi to Shanghai tested positive for the virus that causes COVID-19 upon landing in the Chinese city. The passengers presented negative COVID-19 tests taken within 96 hours of their flight, which is a requirement for all passengers entering, transiting through and leaving the United Arab Emirates (UAE). They also did not exhibit symptoms, an Etihad Airways spokesperson told Al-Monitor.

In accordance with Chinese aviation law, Etihad canceled an Aug. 17 flight from Abu Dhabi to Shanghai and an Aug. 18 flight from Shanghai to Abu Dhabi.

The Gulf carrier is now instituting even stricter pre-flight testing regulations for future Shanghai flights. Passengers traveling there will now have to present a negative COVID-19 test completed within 48 hours before boarding the flight or proof of a test done at the airport from which they arrived to Abu Dhabi, the spokesperson said.