Police have detained a man who posted seditious material and insulted Islam on Facebook, which went viral since Monday (April 25).

Penang police chief Datuk Abdul Ghafar Rajab said the 26-year-old who works as a factory worker was picked up in Sungai Petani, Kedah at 12.15am today.

"On Monday, a police officer on duty at the state police headquarters operations room was alerted about the posting via WhatsApp," he said in a statement here.

He said police had seized the suspect's smartphone which was believed to have been used to upload the posting.

He added that the man will be remanded three days to facilitate investigations and urged the people not to touch on religious sensitivities on social media as this could affect racial and religious harmony in the country.