The sectarian violence in Pakistan took a turn for the worse when suspected Shia militants gunned down the chief of the banned Sunni extremist organisation Sipah-e-Sahaba, Maulana Azam Tariq, and four of his associates in Islamabad.
Tariq, who won last year's national assembly polls as an independent and later became a supporter of Prime Minister Mir Zafarullah Khan Jamali, was ambushed on the Kashmir Highway.
The assailants were in a Pajero.
Interior Minister Faisal Saleh Hayat announced his death in the National Assembly, which was then prorogued as a mark of respect.
The murders followed a series of attacks on the Shia community in the recent past.
Pakistan's Geo television showed images of the victims lying slumped in the car amid shattered glass.