Security forces captured a Tiger training camp and killed two rebels during "intense fighting" along the north eastern district of Mullaittivu on Friday, the ministry said in a statement.
It said fresh fighting near the rebels' de facto capital of Kilinochchi on Friday killed two more fighters while some soldiers sustained minor injuries.
The military said its troops were "taking no chances", trying to evade mines as they moved towards the western outskirts of Kilinochchi.
"Confrontations have become intense as the troops began closing in...
Tigers are now on the defensive, trying to block the passage of the troops," the statement said.
The rebels did not comment on the defence ministry statement.
The Colombo-based government blocks independent journalists from travelling to the frontlines, making it impossible to verify military claims.
Sri