The attacks were carried out in Sancharak, Sozma Qala and in the provincial capital, also Sar-i-Pul, said Zabihullah Amani, a spokesman for provincial governor.
Nineteen other security forces were injured in the assaults, he said.
One member of security forces was captured by militants.
The official said that Taliban also suffered casualties in the attacks, but there was no exact figure.
Separately, four civilians were killed when a roadside bomb exploded in Ghazni province last night, officials said.