Protesters called on Monday for Jordan's government to resign over its failure to prevent the murder of Christian writer Nahed Hattar, as the killing was condemned internationally.
A bearded assailant on Sunday shot dead Hattar, 56, on the steps of a court in central Amman where he was facing trial for sharing an anti-Islam cartoon on social media.
His family has so far refused to collect his body for burial, charging that authorities were warned of threats to Hattar's life and had failed to act.
Hundreds of sympathisers and members of the writer's tribe protested outside the premier's office on Monday.
"The people want the fall of the government... No security, they killed Nahed in Amman!" they chanted.
Carrying his portrait, they called for the resignation of both Prime Minister Hani al-Malki and Interior Minister Salama Hammad.
"We handed over 200 names (of people who had threatened the writer) to the governor (of Amman), including that of the assassin, and demanded protection," said Khaled Hattar, one of the victim's brothers.
"But he refused, saying there was 'no real threat'."
Jordan's judiciary on Monday slapped a media blackout on the murder.
The information ministry said the aim was to preserve "the secrecy of the investigation" and that the blackout applied to both social and traditional media.
Hattar had faced charges over a cartoon he posted on Facebook under the title "God of Daesh" (the Islamic State jihadist group) showing a bearded man in bed smoking with two women lying on either side, and addressing God as a servant.
He was hit by three bullets before the alleged assassin was arrested at the scene of the shooting in the capital's Abdali district, official media said.
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- Amnesty criticises government -
The assailant -- bearded and robed like a conservative Muslim -- shot him as he made his way up the steps outside the court.
Amnesty International condemned "this deplorable murder" but also criticised the government.
"By using strict blasphemy laws to prosecute a person for peacefully exercising their right to freedom of expression, Jordanian authorities are fuelling a climate in which violent threats against people whose views are deemed offensive by others are allowed to flourish," said Philip Luther of Amnesty's Middle East and North Africa department.
The UN's cultural agency also condemned the killing.
"This crime constitutes a grave attack on freedom of expression and affects Jordanian society as a whole," said UNESCO director-general Irina Bokova.
The gunman, identified as a 49-year-old Jordanian, gave himself up to police after the killing, a security source said.
A judicial source said the assailant was remanded for 15 days and charged with premeditated murder, facing the death penalty if convicted.
The suspect had acted alone and was not linked to any "terrorist" group, a source close to his interrogation said, asking not to be named.
Meanwhile, well-known Moroccan cartoonist Khalid Geddar said on Monday he had asked for police protection after being threatened for reposting the cartoon that led to Hattar's murder.
Geddar, who runs the satirical magazine Baboubi, reposted the drawing on Facebook on Sunday as a posthumous tribute.
Geddar said he received several threatening messages and comments, including: "Your fate is death and slaughter -- you are the enemy of God."
"I consider this comment to be a direct threat, a call to kill me just because I republished the drawing that led to the death of the Jordanian writer," he told AFP.