Other reports said Ms Bhutto had only been injured and taken to hospital.
Ms Bhutto had just addressed a rally of PPP supporters in the town of Rawalpindi when the rally was hit by a blast.
At least 15 other people are reported killed in the attack.
Ms Bhutto has twice been the country’s prime minister and was campaigning ahead of elections due in January.
GeoTV is also reporting this. It is all over the major newswires.