Bombs in vehicles, along roadsides and carried by suicide bombers are the Taliban's weapons of choice and the leading cause of civilian casualties in Afghanistan.
The United Nations has blamed insurgents for the overwhelming majority of such attacks, and said they have increased sharply this year as the Taliban try to regain territory as foreign troops withdraw.
The two attacks that killed civilians took place in southern Helmand province, while a third killed three policemen in nearby Zabul.
A remote-controlled bomb planted on a motorcycle also killed two people and wounded 10 others in a crowded market in the nearby town of Marjah, police chief Haji Tooryali said.
In Zabul, a roadside bomb killed three policemen and wounded four, deputy provincial governor Mohammad Jahn Rassoulyar said.
Taliban spokesman Qari Yousef Ahamdi denied any responsibility for the Marjah attack. There was no claim of responsibility for the other two attacks.