RAWALPINDI, Pakistan (CNN) -- Pakistan former Prime Minister Benazir Bhutto has died after a suicide bombing that killed at least 14 of her supporters, ex-government spokesman Tariq Azim Khan and Pakistan's primary television networks said.
Bhutto is helped from her vehicle following the October 18 suicide attack on her motorcade.
Bhutto suffered bullet wounds in the aftermath of the bomb attack, TV networks report.
Video of the scene just moments before the explosion showed Bhutto stepping into a heavily-guarded vehicle to leave the rally.
Khan said while it appeared Bhutto was shot, it was unclear if her bullet wounds were caused by a shooting or shrapnel from the bomb.
The suicide attack left at least 14 dead and 40 injured, Khan told CNN in a telephone interview.
The attacker is said to have detonated a bomb as he tried to enter the rally where thousands of people gathered to hear Bhutto speak, police said.
Video from the scene of the blast broadcast from Geo TV showed wounded people being loaded into ambulances.
Up to 20 people are dead, the report said.
Earlier, four supporters of former Pakistan Prime Minister Nawaz Sharif died when members of another political party opened fire on them at a rally near the Islamabad airport Friday, local police said.
Several other members of Sharif's party were wounded, police added.
While President Pervez Musharraf has promised free and fair parliamentary elections next month, continued instability in the tribal areas and the threat of attack on large crowds has kept people from attending political rallies and dampened the country's political process.
Campaigners from various political groups say fewer people are coming out to show their support due to government crackdowns and the threat of violence.
At least 136 people were killed and more than 387 wounded on October 18 when a suicide bomber attacked Bhutto's slow-moving motorcade. The former PM returned to the country after eight years of self-imposed exile to a massive show of support in the southern port city of Karachi.
Bhutto called it "an attack on democracy" and vowed it would not deter her political campaign.
Thursday's violence come less than two weeks ahead of January parliamentary elections and as many days after President Pervez Musharraf lifted a six-week-old state of emergency he said was necessary to ensure the country's stability.Critics said Musharraf's political maneuvering was meant to stifle the country's judiciary as well as curb the media and opposition groups to secure more power