Chinese authorities have arrested six Vietnamese fishermen, officials say, in a move that could increase tensions in the South China Sea.

Vietnam said the men were detained in disputed waters where the two countries have been confronting each other over a Chinese oil rig.

China says the fishermen were in Chinese waters off Hainan island.

The two are locked in an intensifying dispute over territory in the South China Sea.

Each side has accused the other of ramming their boats in the area around the Haiyang Shiyou 981 oil rig.

Earlier this year Vietnam protested against China moving the rig to waters also claimed by Vietnam, at a spot near the disputed Paracel Islands.

Read more: http://www.bbc.com/news/world-asia-28168447