AFP/ Karachi
A key witness in the murder of prominent Pakistan rights activist Sabeen Mahmud has been shot dead, police said Tuesday.
Ghulam Abbas, Mahmud's driver, was targeted by unknown gunmen when returning to his house from a local mosque on Monday evening, police said.
Forty year-old Mahmud, who ran The Second Floor cafe in Karachi that regularly organised debates and art events, was killed in April when gunmen attacked her car as she left the venue after hosting a talk on rights abuses in Baluchistan.
Police sources said that Abbas was a key witness in the murder as he was sitting in the rear seat of the car and Mahmud was in the driving seat when she was fatally hit by five bullets.
"We are probing the murder from all angles," Malik Altaf, a senior police investigator said.
"There is a high probability that this murder might be linked with that of Sabeen's," he told AFP.
However, police also said that Abbas had already identified the suspected killers in a magistrate's court a few weeks ago.
Mahmud's murder sent shockwaves through progressive society in Pakistan, as it was seen as trying to silence liberal and dissenting voices in the country.
Resource-rich Baluchistan is the largest of the country's four provinces and also its most impoverished.
It has been racked by a separatist insurgency since 2004, with separatists demanding more autonomy and control over gas and mineral resources. They have frequently targeted security forces and police for years.
Human rights groups allege the security forces have committed abuses, accusing them of picking up non-militant separatists -- including academics and students -- torturing them and dumping their bodies on the streets. Others simply disappear, activists say.
Mahmud was shot dead just minutes after she hosted a seminar on abuses in the troubled province.
Police are examining whether Mahmud was targeted because of her work at the cafe, which held talks against religious extremism as well as state brutality.