A 17,000-ton drilling rig had broken lose and was blown ashore on Scotland's Isle of Lewis and officials warned on Wednesday that it is now leaking oil.

According to the Maritime and Coastguard Agency (MCA), two of the four holding tanks aboard the Transocean Winner have been damaged and are releasing an unknown amount of diesel oil. The rig was reportedly carrying 280 metric tonnes of oil.

Environmentalists say that the accident, which occurred in the North Sea off Scotland's outer Hebrides, highlights why offshore oil drilling is so risky and controversial, as it poses a grave threat to local ecosystems and economies.

"Leaking diesel oil could create a serious problem for wildlife in such a sensitive area, which is often home to whales, dolphins and important seabirds," said Friends of the Earth Scotland director Dr. Richard Dixon. "The local community is dependent on tourism and fishing, both of which would be badly impacted by a serious spill."

Further, Dixon notes, "Just seven miles west from the grounding site is the EU-protected Loch Roag coastal lagoons, which form a rare and valuable habitat of marine grasses, seaweeds and sponges."

According to the BBC, the Transocean rig was being towed from Norway to Malta when it hit bad weather Sunday evening. The tow line reportedly broke in the early Monday hours.

"If the diesel oil leaks into the environment, the clamor for answers as to why such a risky trip was attempted will grow much louder," Dixon warned. "Why was the rig taking this dangerous route off the mainland in such a storm? How do we make sure that companies don't repeat these mistakes?"

"Lessons from this incident will need to be learnt, and quickly," he continued, "with further decommissioning of North Sea rigs expected and climate change expected to create more powerful storms and difficult seas."

Scottish Environment Secretary Roseanna Cunningham agreed, saying, "This whole incident raises serious questions about why this rig was being towed through Scottish waters when such stormy conditions were forecast, and the deputy first minister has been in direct contact with the UK government about this very point."

For a look into the scale of the accident, and its potential consequences, AP posted an alarming video of the rig being battered by the waves along the Scottish coastline.