Taiwanese authorities say an official Chinese ship has sailed in "prohibited" waters near the Kinmen Islands, which are effectively controlled by Taiwan.

Coast Guard Administration officials said the Chinese ship on Tuesday approached the islands, which lie near the city of Xiamen in China's Fujian Province.

Taiwan has designated what it calls "prohibited" and "restricted" waters around the islands.

The officials said radio communication and other means were used to warn the Chinese vessel not to enter the area without permission, but the vessel remained in the waters for about an hour.

Last week, a Chinese fishing boat capsized near Kinmen while being pursued by the Taiwanese coast guard. Two of the four people onboard died. China responded sharply to the incident and announced that it would step up "patrols" in the area.

Chinese authorities are previously thought to have tacitly approved the existence of the Taiwan-designated "prohibited" and "restricted" waters. But after the deadly incident, China stated that there is no such thing as "prohibited" or "restricted" waters.

Observers say China's moves are believed to be attempts to narrow the scope of Taiwan's law enforcement. They add that China may repeat such maneuvers in the future.