"An unidentified flying object was spotted over the waters near the city of Rizhao," the bureau said in a message sent to fishermen, as quoted by the Chinese media.
The notice added that the relevant authorities were preparing to shoot the object down. In this connection, the maritime bureau urged fishing boats to follow safety rules, the news outlet reported. The maritime authority also requested fishermen to take photos of the object if it falls nearby.
The bureau did not specify what the flying object was and whether it was eventually taken down, according to the media.
The Unites States and Canada shot down a total of three high-altitude airborne objects in February, including one that was taken down on Saturday over Canada's Yukon territory.