Well-known Pakistani journalist and human rights activist Khurram Zaki has been shot and killed by Taliban militants.
Zaki was eating at a restaurant in the north of Karachi when gunmen opened fire from motorbikes, the BBC reported.
A spokesperson for a splinter group of the Pakistani Taliban said it was responsible for the shooting.
Zaki worked at the website Let Us Build Pakistan, which condemns religious extremism and promotes democratic and progressive values in the country.
"Sadiq Khan is not a Pakistani," he wrote. "He is a Britisher. Credit for his rise and success goes to his own hard work and the equal opportunity quality of the British system. Pakistan and Islam have played no role in his meteoric rise.
"I am celebrating the greatness of Western Secular Democracy. In this day and age of Takfiri Deobandi/Wahabi terrorism and Islamophobia, London has risen above discrimination and bigotry and emerged as great centre of human civilisation setting a great example for the world."
It was believed Zaki was targeted because of his campaign against Red Mosque cleric Maulana Abdul Aziz, who Zaki says incited hatred against Shiite Muslims, Dawn News reported.
In a statement posted online, Let Us Build Pakistan editor Ali Abbas Taj wrote:
Shaheed Kurram Zaki was a bigger journalist and rights activist with more valuable credentials and contributions than those in mainstream media.
In boldly highlighting and supporting the rights of Sunni Barelvis, Shias, Sufis, Ahmadis, Hindus and Christians, his contribution as citizen journalism was much bigger than all journalists combined in Pakistan.
His death is the grim reminder that whoever raises voice against Taliban ... in Pakistan will not be spared. And when they have to murder, they never fail.
To honour and preserve the memory of our dearly departed colleague, LUBP is setting up the Shaheed Khurram Zaki Trust to ensure the well being of family members and children of deceased activists killed by terrorists regardless of their sect or faith background.