Kabul police spokesman Ferdaws Faramarz said the first two explosions took place 15 minutes apart and a third targeting a police vehicle took place two hours later.
No group immediately claimed responsibility.
It wasn’t yet clear what caused the blasts. The majority of bomb attacks in the capital Kabul in recent months have been sticky bombs — explosive devices with magnets that are attached to vehicles and detonated by remote control or timer.
The first blast targeted a civilian car wounding both travelers inside the vehicle. The second explosion targeted a car in a northwestern Kabul neighborhood in which national army soldiers were traveling, killing two soldiers. A civilian passerby was also killed.
The third explosion destroyed a police car in western Kabul, killing two police officers.
Kabul police said investigations were underway.
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The Islamic State group’s local affiliate has claimed responsibility for some of the attacks, but many go unclaimed, with the government putting the blame on the Taliban. The insurgent group have denied responsibility for most of the attacks.