Islamic State (Isis) militants are believed to have executed five men after their wives did not wear hijabs (Islamic headscarves) properly.

The executions were reportedly carried out in the al-Muthanna area of Mosul, the stronghold of Isis in northern Iraq, according to the Allhurra website.

Reports suggest the religious police appointed by the extremist group have set up roadblocks in various Isis-controlled regions to ensure women dress up in the Islamic way.

Though the report could not be independently confirmed, the Sunni Islamist organisation had imposed similar harsh punishments adhering to the Shariah law, the hard-line Islamic rules.

In one of the latest violent incidents, the Isis has released a video of a child soldier executing two Russian spies.