Protesters denounced the hanging. Some religious and political leaders, as well as militant groups, defended the killer.
Most schools closed down in the capital, Islamabad, and in the nearby garrison city of Rawalpindi, in fear of violence.
Qadri’s supporters blocked roads and burned tires, and many shopkeepers shuttered their stores.
In Qadri’s hometown of Rawalpindi, a mob ransacked a vehicle belonging to a local TV channel and attacked reporters, and, in the port city of Karachi, his supporters briefly skirmished with police.
Qadri was on guard duty for secular governor, Taseer, who was campaigning in support of a Christian woman.
She had been jailed for years, accused of blasphemy and of desecrating Islam’s holy book, the Koran.
Taseer had called for reforms of the country’s harsh blasphemy laws, which impose the death sentence for insulting Islam.
Qadri, who repeatedly shot Tasser at a marketplace, said he did so because the governor spoke out against blasphemy laws.