Agung Kurnia Ritonga, 22, a student at the University of North Sumatra in Medan, was found guilty of insulting Islam and is facing 18 months in jail. (photo supplied)

Prosecutors in Indonesia have demanded an 18-month jail term and a $715 fine for a Christian student accused of insulting Islam.

Agung Kurnia Ritonga, 22, a student at the University of North Sumatra in Medan, is currently on trial for insulting Islam in an Instagram post by mocking the burning of an Islamic flag in October last year.

Three Muslim youths in Garut, West Java burned a tawhid flag presumed to belong to Hizb ut-Tahrir, a banned militant group on Oct. 21, 2018.

Ritonga’s Instagram post on Oct. 24, was said to have insulted the tawhid flag that has script describing the monotheistic God in Islam and God himself.

"What's the matter if the tawhid flag is burnt? Your God apparently gets burnt also? So, don't take many recitations that teach culture, that makes fools. Your God is just silent over there, playing guitar, getting drunk, and writing porn poetry, why are you so busy?" Ritonga wrote.

He was arrested the next day after hundreds of Muslims surrounded his house in protest.

During trial proceedings this week, prosecutors told the panel of judges that Ritonga’s actions could have damaged interreligious harmony.

Muhammad Irwansyah Putra, a local mosque official who made the initial blasphemy complaint, said he was satisfied with the trial’s outcome and agreed with the jail term demanded by prosecutors.

“I agree with the proposed sentence as it should appease anger and avert possible violence,” he told ucanews.com.

Hamdan Hasonangan Harahap, Ritonga’s lawyer, said the student had shown remorse and apologized to Muslims.

“What he wrote did not aim to insult Muslims, he only wanted to debate [with them],” he said.

Bonar Tigor Naipospos, deputy director of Setara Institute for Democracy and Peace, regretted that such a case required a jail sentence.

“It was because of pressure from radical Muslim groups,” Naipospos said.

He referred to the case of a Buddhist woman, also from Medan, who was jailed for 18 months in August last year for complaining about the noise from a local mosque’s loudspeakers during the call to prayer.

The blasphemy law is discriminatory, he said.

Judges are expected to deliver their verdict next week.