Thousands of people attended the funeral of Jordanian writer Nahed Hattar on Wednesday amid tight security, three days after he was shot dead on the steps of an Amman court.

Wrapped in the national flag, his body was buried in his hometown, Fuhais, 20 kilometres (12 miles) north of the capital.

Hattar, a 56-year-old Christian, had been on trial for insulting Islam after he shared a cartoon on social media that mocked Islamists.

He was shot three times by a bearded assailant who was arrested at the scene. 

Thousands of people -- members of his family and sympathisers -- attended the funeral, waving Jordanian flags and carrying signs saying "No to extremism, no to violence, no to killing".

After prayers at a church in the town, his body was buried in the presence of several dignitaries including former prime minister Abullah Nsour.

Dozens of police officers also attended the ceremony.

Hattar's family have accused the authorities of failing to protect Hattar despite their appeals after he was threatened.

They also called for the resignation of both Prime Minister Hani al-Malki and Interior Minister Salama Hammad.

A source close to the family said they had reached a deal with the authorities, who promised to arrest and place on trial everyone who had threatened the writer or called for his murder.

Hattar had been arrested on August 13 after posting a cartoon on Facebook under the title "God of Daesh" (the Islamic State jihadist group). He was later released on bail.

It showing a bearded man in bed smoking with two women lying on either side, and addressing God as a servant.

He explained on Facebook that the cartoon made fun of "terrorists and how they imagine God and heaven, and does not insult God in any way".

The leftist writer was known for his support of the regime of President Bashar al-Assad in Syria.

His suspected killer was charged with premeditated murder, terrorism and possession of an illegal firearm. If found guilty, the suspect could face capital punishment.