Provincial officials said a police vehicle hit a roadside bomb in Herat province, Khaama Press reported. At least two police officers were injured.
Abdul Rauf Ahmadi, a spokesman for the provincial security commander, said no one immediately claimed responsibility for the incident.
In Helmand province in the south, officials said at least 23 Taliban militants, including Pakistani and Chechen fighters, were killed in clashes with police that began Monday after the militants attacked a police checkpoint.
Defense Ministry spokesman Gen. Zahir Azimi said the sides were exchanging gunfire Tuesday morning.
Local officials said four Afghan police officers died in the incident in Sangin district. However, Taliban militants claimed 10 police officers and a commander were killed, Khaama Press reported.
Azimi said several religious schools teaching Taliban militants had closed and fighters were deployed to Afghanistan.