A suicide blast in a market in the northwestern city of Peshawar has killed eight people and wounded 30, according to Al Jazeera sources.

A Pakistani official told the AP news agency that the blast happened on Tuesday near a Shia mosque and a hotel frequented by Shias.

The blast came as talks between government negotiators and representatives from the Pakistani Taliban designed to end years of fighting were delayed. The Pakistani Taliban denied any involvement.

Hospital sources in Peshawar, a sprawling, dusty city on Pakistan's unstable frontier with Afghanistan, told the Reuters news agency that several dozen people were wounded.

A separate attack on a train in the Landhi area of Karachi has derailed five carriages, killing six people and injuring several more, Al Jazeera sources in the area say.

Source: Al Jazeera and agencies