A suicide attack on a police station in the eastern city of Jalalabad left at least 10 police officers dead. A presidential election is due on April 5.
Kandahar blasts Tuesday night killed nine people, including five children, as insurgents fight intensified NATO-led operations in the south of Pakistan.
Working with criminal gangs, Taliban are planting roadside bombs and extorting money in Afghanstan's northern provinces.
Militant attacks are increasing outside the Taliban's southern stronghold, such as Sunday's on President Hamid Karzai.