Officials say a roadside bomb attack has killed at least 11 people in northwestern Afghanistan, just days after the Afghan Taliban leader urged his fighters to avoid killing civilians.

Afghanistan's interior ministry says a bomb exploded near a police vehicle in Badghis province late Monday, killing two police officers and nine members of the same family.

Authorities say a police convoy had stopped to pick up a family that needed a ride into town.

An interior ministry spokesperson blamed the Taliban for the attack, calling it “un-Islamic” and another example of insurgents targeting civilians.

Monday's bombing was the latest instance of violence during the major of Islamic holiday of Eid el-Adha, or the “feast of sacrifice,” which began on Sunday.

On Friday, a website used by the Taliban posted a message purported to be from Afghan Taliban leader Mullah Omar, who called on insurgents to “take every step to protect the lives and wealth of ordinary people.”

The statement said any Taliban fighter proven to have killed civilians would be subject to punishment under Islamic law.

Two days later, a suicide bomber killed seven people in the northern province of Baghlan, in an attack that was targeting a local tribal elder.

A roadside bomb also killed a district police chief and two of his bodyguards on Sunday in Helmand province – the heart of the Taliban's traditional stronghold in the south.

NATO Commander John Allen has condemned the violence, saying it was “despicable” for insurgents to carry out attacks during the Islamic holiday.

He said Taliban fighters were “either uninformed or don't care” about Mullah Omar's call to avoid civilian casualties.