Yalcin Akdogan, who was visiting the southern town of Kilis, said two of the projectiles struck the town in the morning, slightly injuring six Syrian refugees and 10 Turkish nationals. Three more hit Kilis in late afternoon, killing one person and wounding 10 others.
The deputy premier said 45 rocket rounds have been fired at Kilis since Jan. 18, killing 16 people including today's fatality. At least 62 people have been wounded since then.
"Their intervention is continuing," Akdogan said in televised comments.
The wider province of Kilis borders areas in Syria that are hotly contested by Syrian anti-government rebels, Kurdish factions and Islamic State militants. The governor for Kilis has said that the rocket projectiles have mostly been fired from IS-controlled territory.
News reports said police used water cannons today to disperse Kilis residents who had gathered near the governor's office to demand greater protection.