The explosion occurred near a medical facility in Bazid Khel village, Dawn newspaper reported. At least 15 more people were injured.
The report quoted police sources as saying vaccines and other supplies for an anti-polio campaign were being distributed at the village medical facility when the remote-controlled bomb went off.
Police official Najeebur Rehman said at least six people died including four police officers. The other two killed were members of a peace committee, Dawn said. The injured were taken to a hospital in Peshawar.
The police officers killed were members of a squad guarding the health facility.
Xinhua News Agency quoted a hospital official as saying nine of the injured were police officers, with three of them remaining in critical condition.
The Dawn report said another bomb was found at the site but it was defused.
Peshawar is the capital of Khyber Pakhtunkhwa province, which has witnessed a number of such attacks blamed on the banned Tehrik-i-Taliban Pakistan militant group.
No group or militant organization, however, had claimed responsibility for the latest attack.
A number of polio health workers have similarly been attacked and killed in recent months.
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