"In the first incident, a convoy of security forces, heading for the Repeater Tower of Nepal Telecom at Machhyang village, struck the landmine at Chuchchebari in the district but no one was killed," police said.
"However, three soldiers, travelling on foot were killed and another one injured in the second explosion at Madanpokhara in Palpa district," police said.
The second explosion occurred about three kilometres (1.8 miles) from the first one.
The injured and the dead soldiers were airlifted to Kathmandu later Sunday.