Japan has arrested the captain of a Chinese fishing boat that collided with two Japanese coastguard vessels near disputed islets in the East China Sea, prompting anger in Beijing and reigniting territorial tensions.
Following are some facts about maritime disputes, a long-term source of friction between the two neighboring countries:
The incident took place near a group of East China Sea islets -- called Senkaku in Japan and Diaoyu in China -- over which Tokyo and Beijing claim sovereignty.
The group of uninhabited islands are thought to lie near potential oil and gas reserves in an area rich with fish, west of Japan's Okinawa island, northeast of Taiwan and east of China's southeastern Fujian coast.
Tokyo says the islands were unclaimed until 1885 when it began surveying them and that they were then officially incorporated into Japanese territory.
China says they were used by its fishermen for several centuries after they discovered them in 1403, and were administered as part of Taiwan.
The dispute gained significance after a 1969 United Nations report said there might be large oil reserves in the vicinity. Since then, surveying has been a sensitive issue.
The larger drive to secure the East China Sea's natural gas resources has seen overlapping claims from Japan and China of Exclusive Economic Zones (EEZ). Both claim 200 nautical miles of EEZ, although the East China Sea is only 360 nautical miles wide. Japan says the median line between the two countries' coasts marks the boundary between their exclusive economic zones. China says the boundary is defined by its continental shelf, extending its zone beyond the median line.
DEVELOPMENT OF GAS FIELDS
The two countries are also at odds over China's exploration for natural gas in the East China Sea. In 2008, they agreed in principle to solve the feud by jointly developing gas fields.
Talks began in July on an international treaty on the joint development but progress has been slow and Japan has accused China of drilling for gas in violation of the deal.