The gunmen struck in Garhi Sohbat Khan on the outskirts of Peshawar, the capital of northwestern Khyber Pakhtunkhwa province, attacking a private vehicle carrying the three soldiers, said Shaukat Khan, a senior police officer.
The attackers used handguns to target the soldiers, who were returning from a military dairy farm after fetching milk for officers, Khan said.
No one claimed responsibility, but terrorists have been involved in multiple such attacks in and around the provincial capital surrounded by lawless tribal regions, the Associated Press reported.
Dad Mohammad, another area police officer, said the incident was second such attack in this area - which is close to Mohmand tribal region. Last week gunmen shot and killed a prominent physician who was instrumental in anti-polio campaigns, he said.
The Mohmand tribal region had been a longtime hotbed for militants and the Pakistani army has carried out several operations to eliminate militant hideouts.
But the militants have repeatedly struck back. Last Friday, a suicide bomber killed 36 worshippers in a mosque during weekly prayers in the Ambar area of Mohmand. Jamaatul Ahrar, a breakaway faction of the Taliban, claimed responsibility for that attack.