In western Herat province, two police officers died in a roadside bombing while in neighbouring Farah province, three were killed when a bombing targeted their checkpoint.
No one immediately claimed responsibility for the attacks but officials in both provinces blamed the Taliban.
Insurgents have been active in both Herat and Farah as the Taliban stepped up their attacks against Afghan security forces across the country this year.
Jelani Farhad, spokesman for the provincial governor in Herat, said that along with the two who died in the attack there, three other officers were wounded. The police were on a routine patrol in Ghoryan district when the bomb exploded on Tuesday, he added.
In Farah province, where the three officers were killed, Mohammad Naser Mehri, spokesman for the provincial governor, said insurgents attacked the checkpoint and triggered a gunbattle that lasted for two hours.
And in yet another report, district police chief Rahmatullah Khan said that one policeman and six Taliban were killed in a gunbattle overnight in northern Takhar province, in Khoja Ghor district.
The Taliban claimed that their fighters had seized several checkpoints in the district, but Khan said security forces were able to push back the insurgents and regain control of the security checkpoints.