One of the founders of "Islamic State of Iraq and Syria" (ISIS) propaganda agency Amaq, Rayan Mashaal, was killed in an airstrike in the Syrian town of al-Mayadeen in Deir Ezzor, social media reports said Wednesday (May 31st).

His brother announced the death, which reportedly occurred on Monday, in a widely circulated social media post.

Mashaal, 31, also known as Baraa Kadek, founded opposition Halab News Network, leaving it in 2013 to join ISIS. He was later accused of handing over Syrian activists to ISIS, according to Arabic media reports.

Widely considered the group's primary news outlet, Amaq agency releases statements through Telegram, an encrypted messaging app.

Mashaal had been a well-known media activist before joining ISIS, opposition news network Aleppo24 executive director Mohammad Khaled told AFP.

According to Khaled, who said he met him in 2012, Mashaal worked as a media activist in Aleppo until late 2013, when he announced he was moving to "the land of the caliphate" in ISIS-held al-Bab.

From there, he moved to al-Raqa, ISIS's Syrian stronghold, but fled to al-Mayadeen four months ago as the Syrian Democratic Forces (SDF) approached the city, Khaled said.

"We knew that he was founding this [Amaq] agency in 2014 because he invited all the activists in Aleppo to join him," Khaled said.

Ongoing media war

"The killing of Rayan Mashaal has positive implications in terms of the ongoing media war," said Syrian journalist Akram Saleh, who is currently reporting from rural al-Raqa.

ISIS has been trying to impose its deviant ideology through its media machine, he told Diyaruna.

"The media war does not end with Mashaal’s killing, as there are many other media channels ISIS employs, which should be tackled," he said.

These include al-Muyassira and al-Bayan newspapers, which are printed or distributed on CDs, in addition to al-Bayan Radio which broadcasts in various cities under ISIS control, including Mosul and al-Raqa.

Al-Bayan Radio was taken offline on February 25th by an Iraqi airstrike on Mosul.

ISIS well understands it is facing "great resistance to its media", Saleh said, "and is therefore trying to survive despite the ban imposed on it, by securing a large number of social network accounts".

The group's focus on its media outlets indicates the importance it places on controlling its image and message, he said.

"A large number of ISIS elements work in its media machine, based on what I have personally witnessed while covering the fighting in northern Syria," he said.

"I encountered many dead ISIS elements who had in their possession cameras and memory cards with much information, photographs and promotional materials, confirming that they were part of the media system," he added.

As the group's areas of control shrink, Saheh said, it is fighting a media war to defend its main stronghold.

The elimination of Mashaal has many positive implications, Ibn al-Waleed Centre for Studies and Field Research new media department director Mazen Zaki said.

ISIS is in "disarray following the losses it has suffered in Syria and Iraq", Zaki told Diyaruna, adding that Mashaal's killing has compromised its ability to conduct psychological and media warfare.

ISIS’s media operatives have served as "the group’s mouthpieces", he said, "and with a blow like this, there will be a negative impact on morale among the group’s remaining elements".

Waleed Abu al-Khair in Cairo contributed to this report