China is ramping up its presence east of Taiwan in an apparent bid to establish jurisdiction in the waters and counter Japanese-Philippine cooperation in the area — a move that could aid in a blockade or quarantine of the island, according to a new study.

The moves, which follow a May announcement by Tokyo and Manila launching maritime boundary talks for the area, include a “series of unprecedented operations” in the Philippine Sea by Chinese survey and law enforcement ships, the Center for Strategic and International Studies’ Asia Maritime Transparency Initiative said in the study published this week.

The operations include the questioning of nearly 200 commercial vessels transiting the area, with Chinese ships demanding their ports of call and crew details, while also deploying a sustained law-enforcement presence, according to the report.