Mubasher: The oil spill from the Iranian oil tanker, which exploded and sank in East China Sea last week, has spread widely during the past few days, causing a serious threat to marine life.

The slick has quickly tripled in size, covering a total surface area of 332 square kilometers, up from 101 square kilometers seen on Wednesday, data by China's State Oceanic Administration showed.

The spill is now about the size of Malta, and much of the environmental danger may be lurking underneath the water, Germany’s Deutsche Welle (DW) reported on Monday.

The environmental damage would depend on “how much of the condensate burned off or evaporated at the surface before the vessel sank as well as how much is leaking underneath the water,” according to DW.

By 11:00 am GMT, Brent crude futures inched down 0.04% to 68.58 per barrel (pb), while Nymex crude edged up 0.05% to 63.40 pb.

Sanchi, the Iranian oil tanker, burnt near China’s coast, leaving behind the largest oil slick since 1991. The sinking had been carrying around 136,000 tonnes of oil.