Pakistan's Prime Minister Imran Khan has attacked hardliners and appealed for calm after the acquittal of a Christian woman convicted of blasphemy.
In a televised broadcast, Mr Khan said hardliners were "inciting [people] for their own political gain", claiming they are "doing no service to Islam".
The landmark Asia Bibi case has already set off violent protests by hardliners who support strong blasphemy laws.
Her lawyer has told the BBC she would need to move to abroad for her safety.
Asia Bibi was convicted in 2010 after being accused of insulting the Prophet Muhammad in a row with neighbours.
She always maintained her innocence, but has spent most of the past eight years in solitary confinement.
Wednesday's verdict by the Supreme Court triggered demonstrations in Karachi, Lahore, Peshawar and Multan. Clashes with police have been reported.
A leader of the hard-line Islamist Tehreek-i-Labaik party, Muhammad Afzal Qadri, said all three Supreme Court judges "deserve to be killed".
The Red Zone in the capital Islamabad, where the Supreme Court is located, has been sealed off by police.
Late on Wednesday, Mr Kahn said: "Which government can function like this, blackmailed by protests?. . .
"And who suffers due to this? Our Pakistanis. The common people, the poor. You block the roads, you rob people's livelihood. . .
"This is not the service of Islam, this is enmity with the country. Only anti-state elements talk like this, that kill the judges, start a revolt in army. . . They are only trying to beef up their vote bank. "
What was Asia Bibi accused of?
The trial stems from an argument Asia Bibi, whose full name is Asia Noreen, had with a group of women in June 2009.
They were harvesting fruit when a row broke out about a bucket of water. The women said that because she had used a cup, they could no longer touch it, as her faith had made it unclean.
Prosecutors alleged that in the row which followed, the women said Asia Bibi should convert to Islam and that she made offensive comments about the Prophet Muhammad in response.
She was later beaten up at her home, during which her accusers say she confessed to blasphemy. She was arrested after a police investigation.
What is blasphemy in Pakistan?
Laws enacted by the British Raj in 1860 made it a crime to disturb a religious assembly, trespass on burial grounds, insult religious beliefs or intentionally destroy or defile a place or an object of worship, punishable by up to 10 years in jail.
Several more clauses were added in the 1980s by Pakistan's military ruler Gen Zia ul-Haq:
1980 - up to three years in jail for derogatory remarks against Islamic personages
1982 - life imprisonment for "wilful" desecration of the Koran
1986 - "death, or imprisonment for life" for blasphemy against the Prophet Muhammad