Egyptian authorities have arrested four students for mocking Christian rituals in an online video and ordered them to be kept in custody for four days, a judicial source said Monday.
The university students aged between 19 and 24 were accused of being in "contempt of the Christian religion", the source said.
If tried and found guilty they could face up to five years in prison.
They were arrested last week and remanded in custody by the state prosecutor overnight Sunday.
At the end of January, they posted a video on YouTube in which they were allegedly seen mocking Coptic hymns and prayers.
But they later removed the clip and posted an apology online.
Copts, a Christian minority which accounts for 10 percent of Egypt's 98 million people, have repeatedly complained of marginalisation in the mostly Muslim country.
In recent years they have been targeted by Islamic State group jihadists.
Trials for "contempt" of Christianity are rare in Egypt where more frequently charges are levelled for contempt of Islam usually against liberal Muslim intellectuals.
In 2016 four Coptic teenagers were found guilty of being in contempt of Islam and three of them were handed five-year sentences each after mocking Muslim prayer in a video.
Later that year they fled the country, travelling to Switzerland where they obtained political asylum.