Taipei [Taiwan], April 21 (ANI): A Chinese cruise ship sailed within just two nautical miles (3.7km) of Taiwan's Hengchun Peninsula this week, prompting concern from observers and authorities about a possible 'gray zone' tactic by Beijing, Taipei Times reported.

The incident was reported by Taiwan ADIZ, a civilian Facebook group that monitors Chinese military activity near Taiwan, which posted footage showing the vessel clearly visible from the shoreline in Pingtung County.

The ship was identified as the Gulangyu, a Bermuda-registered cruise vessel with a capacity of up to 1,800 passengers. Taiwan ADIZ noted that if fully occupied, the number of people on board would be roughly equivalent to a battalion-sized military unit.

'If such events become routine, they could pose a serious threat to Taiwan's security,' the group wrote, pointing to the potential for such vessels to be repurposed in conflict scenarios.

Footage allegedly filmed by a passenger on board was later posted to Chinese social media, showing views of the Hengchun Peninsula overlaid with the message in simplified Chinese: 'Taiwan is China,' reported Taipei Times.

Ocean Affairs Council Minister Kuan Bi-ling responded to the incident on Friday, saying the public should stay alert, calling it part of China's broader 'gray zone' strategy--coercive actions that stop short of armed conflict. She added that the government has launched a cross-agency mechanism to monitor maritime activity and would enhance coordination with the Maritime and Port Bureau and national security agencies.

Kuan said that after entering Taiwan's territorial waters around 2pm on Wednesday, the Gulangyu was tracked by the Coast Guard Administration and later exited toward the northeast without altering its speed or course. The incident was believed to be a 'united front' effort by Beijing, she added.

The government is developing a dedicated intelligence and tracking database for vessels operating in sensitive areas, including undersea cable zones, particularly those with Chinese capital or operating under flags of convenience, Taipei Times reported.

The coast guard is charged with monitoring such ships, while the Maritime and Port Bureau enforces the Regulations on the Administration of Innocent Passage of Foreign Vessels. (ANI)