GUNMEN on a motorcycle have killed a prominent women's rights activist in Pakistan just hours after she held a forum on the country's restive Baluchistan region.

Police declined to speculate on a motive for the killing of Sabeen Mahmud but friends and colleagues immediately claimed it was a targeted assassination.

The military and intelligence services still hold tremendous sway despite the re-emergence of democracy in the country.

The gunmen shot both Mahmud and her mother, Mehnaz Mahmud, as they stopped at a traffic light on Friday night in an upmarket Karachi district, senior police officer Zafar Iqbal said.

Later, Mahmud's car was brought to a nearby police station.

The car's white exterior was blood stained while the front driver's side window was smashed and a pair of sandals sat on the floor, surrounded by broken glass.