A nuclear submarine has collided with a cruiser during routine operations off the east coast of the US.
The US Fleet Forces Command said the Los Angeles-class submarine USS Montpelier and the Aegis cruiser USS San Jacinto collided at about 3.30pm on Saturday.
No one was injured, and the extent of any damage to the vessels was not clear on Saturday evening, said Lieutenant Commander Brian Badura.
"We have had circumstances where navy vessels have collided at sea in the past, but they are fairly rare as to how often they do take place," Badura told the Associated Press.
Navy officials said the collision was under investigation, but declined to give details on where the incident took place or what would happen next.
"If we do have an incident that does take place, there are folks that swing into action … to help us make a better, more conclusive explanation of exactly what happened," Badura said.
The news release said overall damage to both ships was being evaluated and that the sub's propulsion plant was unaffected by the collision.
Both ships are based at Norfolk, Virginia, and are operating on their own power.
The Pentagon said late on Saturday it was investigating how the collision had taken place.