Vietnamese fishing craft clashed with Chinese boats near the disputed Paracel Islands last week, underscoring simmering tensions between the two communist countries even as their leaders talk of improving relations.

Chinese vessels damaged a Vietnamese fishing boat with water cannons on June 7 and three days later a Vietnamese fishing boat was attacked and robbed of equipment and its catch, Thanh Nien newspaper reported Sunday. The clashes follow other recent incidents, with a Chinese marine police boat reportedly spraying water cannons at a Vietnamese fishing vessel in late May.

The Paracels remain a flashpoint between Vietnam and China and are part of overlapping territorial claims in the South China Sea, one of the world’s busiest shipping lanes. Vietnam has pushed back after China placed an oil rig in waters near the Paracels in May last year, triggering clashes between boats and anti-Chinese riots in Vietnam.