Oil is leaking from the stranded cargo vessel Brigh Royal, Quang Ngai Port Authority reported yesterday.
The ship, which ran aground off Ly Son Island, is now in a threatened situation and is likely to sink, added the port authority.
According to the provincial border guards, the cargo ship crashed into a reef, causing two large holes at the bottom of two chambers.
The ship was later found to be leaking fuel oil from cracks in its two oil tanks containing 387 tonnes of fuel oil.
The oil slick continues to spread out over the sea surface, said the provincial border guards.