Media playback is unsupported on your device Media caption The attackers were on a motorcycle when they sprayed Chaudhry Zulfiqar's car with bullets

Gunmen have shot dead the prosecutor investigating the murder of Pakistan's ex-leader Benazir Bhutto who was assassinated in 2007.

Police said Chaudhry Zulfiqar Ali was ambushed as he was driving from his Islamabad home to a court hearing in the Bhutto case in Rawalpindi.

Police have not speculated on a reason for the shooting.

Chaudhry Zulfiqar was also the top prosecutor in a case related to the attacks in Mumbai, India, in 2008.

Former Pakistani President Pervez Musharraf has been accused of failing to provide adequate security for Bhutto at the time of her death.

Mr Musharraf, who recently returned to Pakistan after living abroad, is being held under house arrest while the claims against him are investigated. He denies the allegations.

No-one has ever been convicted over the murder of Ms Bhutto.

Police said Chaudhry Zulfiqar was on his way to the anti-terrorism court in Rawalpindi for a hearing on Friday morning when his car was ambushed.

The attackers on a motorcycle sprayed the car with bullets, badly injuring the prosecutor who later died in hospital.

A hospital spokesman said Chaudhry Zulfiqar had been hit by more than seven bullets from the front and side, including one to the head.

A woman pedestrian also died after being hit by Chaudhry Zulfiqar's car after the driver lost control of it, officials said.

Police Supt Jameel Hashmi said one of the prosecutor's bodyguards, who was injured in the incident, had showed "great valour".

"We have got evidence from several witnesses but we cannot disclose anything at this stage," he added.

The attackers fled the scene.

Pakistan's Dawn newspaper reported that lawyers in Islamabad and Rawalpindi have announced a strike over the killing.

Analysis The killing of a top prosecutor of Pakistan's Federal Investigation Agency has brought into focus the complex security situation in Pakistan. While the killers are not yet known, the timing is such that fingers are being pointed at various quarters, including a couple of Jihadist organisations and even the secret agencies. As the former director of FIA and currently its chief public prosecutor, Chaudhry Zulfiqar Ali spearheaded investigations into two high profile cases: the Benazir Bhutto murder, and the Mumbai bombings. He was the main person who pushed the court to expedite proceedings against five members of the Pakistani Taliban faction called the TTP, detained for Ms Bhutto's murder. He also initiated the move to arrest Pervez Musharraf, in the same case, an unprecedented move that reportedly angered some quarters in the military. Besides, he was close to submitting final evidence against seven members of the Lashkar-e-Taiba militant group, being held in connection with the 2008 Mumbai killings. The evidence included planning, training and money-transfer trails in Pakistan that culminated in the Mumbai attacks. Lawyer's murder exposes crises

The claims against Mr Musharraf date back several years.

A UN inquiry in 2010 found that Bhutto's murder could have been prevented, and that Mr Musharraf's government did not provide her with proper security.

Prosecutors issued an arrest warrant for him in February 2011.

He had been in self-imposed exile for several years, but returned to Pakistan in March to try to stand in the forthcoming election.

When the authorities arrested Mr Musharraf last week, Chaudhry Zulfiqar described the accusations as aiding and abetting Bhutto's killing.

Mr Musharraf had blamed Bhutto's killing on Pakistani Taliban chief Baitullah Mehsud, who denied any involvement.

Mr Musharraf's political party, the All Pakistan Muslim League, condemned the prosecutor's killing.

"We vehemently condemn Chaudhry Zulfiqar's murder by armed attackers and seek immediate investigation into the incident which may affect Pervez Musharraf's trial in Benazir case," said party spokesman Muhammad Amjad.

Chaudhry Zulfiqar was also pursuing seven suspected militants over the 2008 Mumbai attacks.

The Pakistani militant group Lashkar-e-Taiba was blamed for the attacks, in which 166 people were killed.

Pakistan has been plagued by violence in the run-up to a general election on 11 May.

Gunmen on a motorcycle killed Sadiq Zaman Khattak, a candidate for the Awami National Party (ANP), along with his young son in the city of Karachi on Friday, police said.

The attack occurred as Mr Khattak and his son were leaving a mosque after Friday prayers. Four people were wounded.

In a separate attack in Karachi, a prominent activist from the Muttahida Qaumi Movement (MQM), Mohammad Adil, was shot dead outside another mosque, police said.