This was the second incident in a week and the third this year involving a Sri Lankan security force member killing his co-worker and then himself.
Navy spokesman Kosala Warnakulasuriya said that the navy sailor had shot dead a female sailor over a personal dispute at the Trincomalee dockyard.
“After killing the female sailor he then shot himself. An investigation into the incident is now underway but this was purely over a personal dispute,” the navy spokesman said.
In a similar incident on Friday a soldier shot dead another soldier and then killed himself in Jaffna.
The shooting took place near a Hindu Temple in Jaffna following over what the army said was a personal dispute.
In March this year three soldiers were killed in Jaffna following a gunfight also over a personal dispute.
The three soldiers were on duty near a Hindu Temple in Chavakachcheri, Jaffna when the shooting took place.