Three Afghan protestors died in a clash with police on Monday as hundreds took to the streets in northern province of Parwan, officials said, DPA reported.
Mohammed Qasim Saedi, head of the Parwan public health department, said the local hospital received three bodies and 25 injured with bullet wounds.
The demonstrators were protesting against the detention of three local religious clerics by NATO forces on Sunday night.
They clashed with police while trying to march to the governor's office in the provincial capital Charikar where Afghan and NATO officials were meeting, said Ahmad Zaki Zahid, head of the provincial council.
He accused some "opportunists and enemies" of infiltrating the protest and shooting at the coalition forces. He said three foreign soldiers were injured in the clash.
"Coalition forces released two of the clerics after investigations while one is still in custody," Zahid said.
About 200 anti-riot policemen were dispatched from Kabul to Parwan to help control the demonstration, a police statement said.
Elsewhere, a roadside bomb hit an Afghan police vehicle in the southern part of the country, killing six officers, a government spokesman said.
The blast occurred in Pirakay area of Ghazni city, Marof Ayobi said.