The two soldiers were shot on Sunday night in the eastern district of Batticaloa, where troops captured the main rebel bastion of Vakarai town on Friday, the ministry said, adding a Tiger rebel was also killed.
The ministry said the two policemen were shot late Sunday in the northern district of Vavuniya.
Five civilians were shot dead by unidentified gunmen in the same region, local police said.
They said the latest victim, a top official at the local transport authority, was shot dead as he rode a motorcycle home with his wife on Monday evening.
Six civilians were gunned down in the same region last week, despite a heavy presence of police and troops.
The ground troops who captured Vakarai in the island's east were clearing the area of mines and booby-traps for a second straight day Monday, military officials said.
Earlier Sunday, the military said it had found 37 dead Liberation Tigers of Tamil Eelam (LTTE) rebels near Vakarai, taking the toll from weeks of fighting to abo