BEIJING (AP) — China’s coast guard says it has released 13 Vietnamese fishermen who were seized off the country’s southern coast in two separate incidents amid tensions over disputed waters.

The coast guard said it released one fishing boat but confiscated a second boat along with fishing gear and fish.

One boat with seven people aboard was seized by Chinese authorities on June 20 and a second with six aboard on July 3, both on charges of fishing illegally in Chinese waters.

Tensions between the two countries spike after Beijing deployed an oil rig in May near the disputed Paracel Islands.