Shootings took place on US base, no indications that non-US citizens were involved, navy says.
Two American sailors were shot dead and one was critically wounded at the US navy base in Bahrain, the navy said on Monday.
There were no indications that non-US citizens were involved, a navy spokeswoman said.
The shootings took place at about 5am (0200 GMT), the navy said in a statement, adding that they were investigating the incident.
The navy gave no explanation for the shootings, which took place in the base's barracks, and said the names of the sailors were being withheld. No further information was immediately available.
Bahrain is the home of the US navy's fifth fleet, which patrols Gulf waters, the Red Sea, the Gulf of Oman and parts of the Indian Ocean.
About 3,000 US personnel, not including the crews of visiting ships, live and work on the base. Staff generally keep a low profile in the tiny Gulf Arab kingdom of about 750,000 people.