Pakistani Prime Minister Nawaz Sharif has described the stoning to death of a woman by her family in front of a Lahore court as "totally unacceptable". Farzana Parveen, who was three months pregnant, was pelted with bricks and bludgeoned by relatives furious because she married against their wishes. Her husband told the BBC that police simply stood by during the attack. Lahore's police chief has denied this and said Ms Parveen had been killed by the time police arrived at the scene. There are hundreds of so-called "honour killings" in Pakistan each year. This incident has prompted particular outrage as it took place in daylight while police and members of the public reportedly stood by and did nothing to save her. Prime Minister Nawaz Sharif has ordered the chief minister of Punjab province to take "immediate action" and submit a report by Thursday evening.