Thousands of protestors rallied in major cities on Friday threatening further protests and anarchy if the government moves to amend a controversial blasphemy law.
A ruling Pakistan People’s Party (PPP) lawmaker sparked outcry last month by seeking to end the death penalty for blasphemy, after a Christian mother of five was sentenced to hang for defaming the Prophet Muhammad (PBUH).
Demonstrators marched in the eastern city of Lahore, the port city of Karachi and the central city of Multan, after influential religious parties called for protests to defend the law.
A crowd of nearly 1,500 people gathered in Lahore, calling for "Jihad" and pledging to sacrifice their lives to protect the honour of Prophet Muhammad (PBUH).
They also warned that attempts to soften the law would trigger nationwide protests.
"Pakistan was created in the name of Islam and we will not tolerate any attempt to amend the law," a leader of the pro-Taliban Jamiatul Ulema-e-Islam (JUI), Maulana Ahmad Khan told the participants.
Former information minister and lawmaker from the ruling Pakistan People’s Party government, Sherry Rehman in November submitted a draft bill in the lower house seeking an end to death penalty under the existing law.
Rights activists also say the law encourages extremism in a nation already beseiged by Taliban attacks.
Addressing a separate rally of over 500 people in Lahore, a leader of the banned charity Jamaat-ud-Dawa (JuD), Husnain Siddiqui said, "We will launch a national movement against all those lawmakers, who support efforts to amend the law."
Politicians and conservative clerics have been at loggerheads over whether President Asif Ali Zardari should pardon Asia Bibi, the Christian mother who was sentenced to death under the blasphemy law.
Pakistan has yet to execute anyone for blasphemy, but Bibi's case has exposed the deep faultlines in the conservative country.
In the port city of Karachi, more than 2,000 people rallied against Rehman's proposed draft bill and demanded the government serve Bibi a severe punishment for insulting Muhammad (PBUH).
Bibi was arrested in June 2010 after Muslim women labourers refused to drink from a bowl of water she was asked to fetch while out working in the fields.
Days later, the women complained that she made derogatory remarks about the Prophet Mohammed. Bibi was set upon by a mob, arrested by police and sentenced on November 8.
Leaders of JUI and radical Jamaat-e-Islami (JI) party warned that the government would "face a strong reaction if Bibi was pardoned."
"The government should forget about amending the blasphemy law as any attempt in this regard will prove fatal," a local religious leader Yahya Ludhianvi said.
Most of those convicted of blasphemy in Pakistan have their sentences overturned or commuted on appeal through the courts.
Rights activists and pressure groups say it is the first time that a woman had been sentenced to hang in Pakistan for blasphemy.
Only around three percent of Pakistan's population of 167 million are estimated to be non-Muslim.