The Royal Navy's newest and largest attack submarine HMS Astute has run aground off Skye, the Ministry of Defence (MoD) has confirmed.
An eye-witness said the sub - described as the stealthiest ever built in the UK - appeared to have grounded.
A Ministry of Defence spokeswoman said: "This is not a nuclear incident.
"We are responding to the incident and can confirm that there are no injuries to personnel and the submarine remains watertight".
The spokeswoman added: "There is no indication of any environmental impact".
The Maritime and Coastguard Agency (MCA) was alerted to the incident at about 0819 BST and confirmed it had run aground.
A spokesman said: "We have sent a coastguard tug to where the submarine ran aground on rocks at the Kyle of Lochalsh near the Skye bridge.
"It will stand by and monitor what will be going on. We think on the rising tide, at around 1800 BST, there should be some movement of the vessel".
A Royal Navy helicopter has also been at the scene.
BBC News
