The state-run Associated Press of Pakistan said at least eight people died including two children and a woman, and 15 more were injured, four of them critically, in the explosion in the crowded Tela Band area near the city's Badaber police station.
China's Xinhua news agency reported the blast killed nine people and wounded a dozen others. The explosion was apparently set off through a remote control. Those killed included three security personnel, the report said.
Separately, China's state-run Xinhua news agency, quoting local media, said at least five police officer died early Wednesday when militants opened fire on their van in Quetta, capital of Balochistan province.
Peshawar, capital of the northwest Khyber-Pakhtunkhwa province, has come under unrelenting violence by extremists and militants from nearby tribal regions, who have been targeting the region's police and security personnel.
On Monday, two separate blasts, both directed at police, killed at least six people, four of them police officers, and wounded 15 others. The region borders Afghanistan.