Islamic State on Tuesday urged Muslims to destroy their satellite TV sets to prevent hostile channels "destroying their beliefs and polluting their ethics.

The ultra-hardline Sunni group issued its call as military pressure increased against it with offensives targeting its strongholds in Raqqa, Syria, and in Falluja, west of Baghdad.

"The enemies of Islam are waging a media war on the Islamic State that is no less dangerous than the military campaign," the group said in a video on its official Telegram account, filmed in Raqqa and monitored in Egypt.

It did not say whether it would try to enforce its appeal in the territory under its control in Syria and Iraq.

It singled out religious channels funded by Saudi Arabia and also showed the logos of al-Jazeera and Orient TV, a channel close to the Syrian opposition, as well as the Egyptian religious channel al-Nas.

The video ended with a scene showing people stamping on satellite dishes to destroy them.

Islamic State declared a caliphate over the territory of Syria and Iraq in 2014.