Tensions high as Chinese vessels shadow Vietnam's oil, gas operations

A Vietnamese coast guard officer speaks on a radio as he monitors a Chinese vessel (top) in the South China Sea, about 210 km off Vietnam's shore, May 15, 2014. [Reuters]

China is sending more ships to Vietnam's exclusive economic zone (EEZ), and the frequency and length of those trips, which have picked up since early May, is raising tensions in the South China Sea.

After a nearly monthlong incursion of a survey ship and its large entourage, more Chinese vessels are sailing through sensitive locations within Vietnamese waters. Vietnam's EEZ extends out 200 nautical miles from the country's coast.