The Islamic State of Iraq and Syria splinter group that has seized parts of Syria and Iraq has told activists in Syria's Deir al-Zor province they must swear allegiance to it and submit to censorship, a monitoring group said on Friday.
The militant group imposed the rules after a meeting on Tuesday with activists involved in media work, the British-based Syrian Observatory for Human Rights said.
International media organisations have little presence in Syria and rely on activists and other sources to provide information on what is happening in the country.
ISIS also told the activists they must recognise the caliphate, based on their strict interpretation of Islam, that it has declared in the parts of Iraq and Syria it controls.
It also said they must stop using the term "Daash" to describe the group.
The Observatory, a Britain-based group which reports on Syria using a network of sources on the ground, said ISIS also banned activists from working with television channels immediately.
They were told that any videos, pictures or written reports needed to be reviewed by the Islamic State's "Information Office," before distribution.
ISIS, which has been fighting rival rebel groups and government forces in Syria, has its own media operation distributed on social media and militant internet forums.
It used its media arm to effect in June when it announced the creation of the caliphate in statements in a series of languages. It has also produced videos showing the group's leader and celebrating its military advances.
Elsewhere in the country, the group has carried out beheadings and mutilations after finding people guilty of crimes and has set strict limits on women's rights as part of its campaign to forcibly impose its radical brand of Islam.
In the eastern city of Raqqa, the Islamic State's stronghold, the group even executed people who had supported the revolt and carried out other actions which have intimidated activists.
In Iraq, the group has been systematically stamping out any religious or cultural influences they deem non-Islamic since their sweep through the north in June.