Japan’s government has come under pressure to assert the country’s territorial claims more forcefully after a group of Hong Kong-based Chinese nationalists landed on a disputed island in the East China Sea.

Criticism by conservative politicians of the government’s handling of the incident, and of two other territorial conflicts, threatens to inject further instability into the disputes – part of a web of competing maritime claims in Asia that are raising tensions across the region.

Japanese authorities were preparing to deport the 14 Chinese activists as early as Friday for unauthorised entry into Japanese territory, without pressing criminal charges, according to local media. That angered conservatives, especially after it was reported that the men had thrown objects at coast guard boats that had tried to prevent their vessel from landing on the island.