Several Vietnamese ships have wrecked in waters off the Xisha Islands in the South China Sea as storms associated with typhoon Conson slammed the area, provincial authorities said Saturday.

The number of casualties is unknown and rescue operations are underway, the maritime affairs bureau of south China's Hainan Province said in a statement Saturday.

The authorities received reports of the wrecks Saturday morning and are confirming the number of wrecked ships and the number of people aboard them.