Beijing (AsiaNews) - Sino-Japanese tensions are up after four Chinese coastguard ships entered the waters of the Senkaku/Diaoyu Islands this morning for the second time in a week. The islands are at the centre of a bitter sovereignty row between China, Japan and Taiwan. Tokyo controls the islands, and Japanese Prime Minister Shinzo Abe vowed to defend them "at all costs".
Chinese vessels entered the waters a few weeks after Beijing announced changes to its approach, unifying government agencies under the Coast Guard. For some observers, this shows that the Chinese government intends to commit more manpower to the islands dispute.
Chinese media have reported that the unified coastguard agency integrates marine surveillance, the existing coastguard (now under the police), fisheries law enforcement and customs' anti-smuggling maritime police.
However, the presence of a large number of official vessels, some of them armed, could increase the chances of a confrontation since a minor slip could quickly escalate.
Tokyo bought three of the five islands from private owners in September 2011, a move that angered Beijing, which responded with a campaign to assert its political and military sovereignty over the area.
Taiwan is also involved in the dispute. Taipei has proposed to develop the area jointly without focusing on ownership.
The value of the archipelago is not clear. Some consider it strategically important given its location in one of the busiest shipping lanes. Others believe that in addition to rich fishing grounds, the seafloor around the islands hold vast gas reserves.
In 2008, in a gesture of détente, Beijing and Tokyo signed an agreement for joint development and research on the islands, which, however, was never implemented.