Kapisa provincial security spokesman Asadullah Hamidi said the explosion occurred in the Ghazi Khel area of Kapisa province, Khaama Press reported.
The Taliban claimed responsibility for the explosion but said five soldiers were killed instead of three injured as reported by local officials.
On Thursday, at least eight militants were killed and four others injured in clashes with Afghan police in Kandahar province in southern Afghanistan, the provincial governor's media office said.
The clashes occurred in the Shahwali Kot district of Kandahar.
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