Taiwan says 11 Chinese government ships have entered waters near the Kinmen Islands. Taiwan effectively controls the islands and designates waters around them as “restricted” and “prohibited.” It bars Chinese vessels from sailing into these waters without permission.

Taiwan’s coast guard says seven Chinese government vessels, including maritime affairs and fisheries ships, intruded into the restricted waters at around 3 p.m. on Thursday.

It says four China Coast Guard vessels sailed into prohibited and restricted waters at around the same time.

Taiwan’s coast guard says the 11 Chinese ships stayed in the waters for about 90 minutes, despite its patrol boats warning them to leave.

It says this marks the fourth time in May that China Coast Guard ships have sailed in formation into the area. It adds that this is the first time China Coast Guard ships have been joined by vessels of other government agencies in entering the waters.

In February, two Chinese fishers died after their boat capsized while being pursued by Taiwan’s coast guard in the waters near the Kinmen Islands. China responded by saying there are no prohibited or restricted waters.

Analysts say China is trying to ratchet up pressure on Taiwan’s Lai Ching-te administration, set to take office on May 20.