Benazir Bhutto has paid the heaviest price possible for her insistence on engaging in democratic politics in Pakistan.

Benazir, twice prime minister and leader of the Pakistan People's Party (PPP), was killed on Thursday evening in what was apparently a suicide attack following gunshots that injured her as she was leaving an election rally in the garrison town of Rawalpindi.

Just 54 years old, and a mother of three children, she died in hospital in Rawalpindi, close to the Pakistani capital Islamabad, at about 6:15pm local time - barely an hour after an unidentified man fired shots at her as she left the rally venue, a fenced off park, before blowing himself up. Some 20 others were killed and dozens more injured.

"She feared something like this would happen, but she was so brave," said PPP spokesperson Farhatullah Babar, who was with Benazir at the rally. Speaking to IPS from Rawalpindi, shortly before the slain leader's body was transferred to her hometown Larkana on a military C-130 plane, Babar added: "She waved at the people, and then there was firing and the blast."