Pakistani intelligence sources have identified three of four Al-Qaeda members who were also believed to have been killed in the attack.
Today's rally, at which demonstrators chanted slogans such as "Death to America!" and "Jihad, Jihad!", followed a protest of 10,000 people in the country's biggest city, Karachi, on 15 January.
An anti-U.S. alliance of radical religious groups called the United Action Forum says it plans to hold two more protests on 20 January, in Peshawar in the northeast and in Lahore in the east of the country.