Narayanganj police yesterday arrested a youth allegedly over a Facebook post demeaning Islam.

Hasan-ul Islam, 29, was arrested in Meghna Ghat area of Sonargaon. He is the son of a brick kiln owner in Fatullah.

Md Shahjalal, inspector (investigation) of Fatullah Model Police Station, said some photos “demeaning Islam” was posted from Hasan's Facebook account.

Following the incident, agitated locals started gathering in front of a local mosque after the Juma prayers on Friday, demanding Hasan's arrest.

Police also detained Hasan's elder brother on that day for interrogation, he said.

“We are looking into the matter and filing of a case is underway,” said the inspector.