Social media channels linked to the jihadist rivals Islamic State (ISIS/ISIL) and al-Qaeda are celebrating and capitalizing on Monday’s assassination of the Russian ambassador in Ankara by a Turkish policeman, who shouted the common battle cry of Islamic extremists as they commit mass murder, “Allahu Akbar,” during the attack.

2) Huge celebration by #ISIS & #AQ accounts for shooting of #Russia ambassador, despite not knowing his allegiance (if any at all) pic.twitter.com/ryXhOQfpLZ — Rita Katz (@Rita_Katz) December 19, 2016

Heavy reports that the 22-year-old attacker Mert Altintas, dressed in a suit and tie when he carried out the assassination, “was filmed giving the ‘tawhid,’ or ISIS’ index finger signal, while shouting ‘Allahu Akbar!’”

The assassination of 62-year-old Amb. Andrei Karlov occurred several minutes into the diplomat’s speech at a Russian embassy-sponsored photo exhibition in the Turkish capital of Ankara.

Altintas reportedly fired at least eight shots, killing the diplomat in front of stunned onlookers. Turkish security forces killed the assassin in a gunfight after the attack.

“Several other people were reportedly also injured in the attack,” notes BBC, adding that the attack came only a day after individuals in Turkey protested Russia’s ongoing support for Syrian dictator Bashar al-Assad.

According to footage of the attack translated by Shaheryar Mirza, the attacker also yelled, “Don’t forget Aleppo, don’t forget Syria! Don’t forget Aleppo, don’t forget Syria! You will not taste the safety unless our fields are safe! Only death can get me out of here. Whoever has a share in this tyranny will pay for it one by one!”

Translation of the Turkish parts in the video of the gunman's words after shooting the Russian ambassador. Video: https://t.co/X9Sb30oIH4 pic.twitter.com/pousiUaFG9 — Shaheryar Mirza (@mirza9) December 19, 2016

Neither ISIS nor al-Qaeda, also known as AQ, have officially taken responsibility for the attack.

Nevertheless, Rita Katz, director of the the SITE Intelligence Group that monitors jihadi websites, wrote on Twitter that both ISIS and AQ accounts have engaged in “huge celebration… for shooting of [Russian] ambassador, despite not knowing his allegiance (if any at all).”

Pro-ISIS and AQ accounts on social media have also been disseminating the video to their supporters.

4) Pro-#AQ media groups circulating footage of shooting, introducing it: "A video which heals the wounded heart of the Ummah." pic.twitter.com/Fdv0J7YXdW — Rita Katz (@Rita_Katz) December 19, 2016

Citing groups affiliated with AQ, Katz notes on Twitter that the assassin has been praised as a “hero who did not stand by… as the Muslims in Aleppo and Shaam [Levant] are being massacred. A true example for the Ummah [Muslim community].”

“Jihadist capitalizing on shooting: disseminating PDF of [Russian] embassies around globe on [social] media in attempt to incite further,” she adds.

6) Jihadist capitalizing on shooting: disseminating PDF of #Russia embassies around globe on soc media in attempt to incite further pic.twitter.com/20otXhIwhk — Rita Katz (@Rita_Katz) December 19, 2016

SITE reports that a pro-Jabhat Fateh al-Sham (JFS) group has been distributing the list of Russian embassies.

JFS, formerly known as al-Qaeda Syrian branch the Nusra Front, claims that it is no longer affiliated with jihadist group.

However, “most Western analysts dismiss JFS’s break with al-Qaida as a feint, seeing it as a long game the jihadist group has been playing for some time across the Middle East and Africa,” according to Voice of America (VOA).

Monday’s assassination comes days after the Turkish government announced it is planning to meet this month with Russia and Iran to discuss efforts to secure a ceasefire in Aleppo – which the Syrian regime, assisted by Moscow and Tehran, recently conquered.

Turkey and Russia have been on opposite sides of the ongoing civil war in Syria.

While Russia has made it possible for Assad to remain in power, Turkey has been backing various armed groups seeking to overthrow the Syrian dictator.

Assad belongs to the minority sect of Shiite Islam in Syria known as Alawite, which has more in common with Shiite powerhouse Iran than Sunni majority Turkey.

Ankara has been trying to mend its trained relationship with Moscow since the November 2015 shooting down of a Russian warplane by the Turkish military.

Earlier this month, Turkish Prime Minister Binali Yildirim declared that the nearly year-long hiatus in relations between Moscow and Ankara is “over” during his first visit to Russia as PM.

Turkey has reportedly expressed regret for shooting down the Russian warplane over the Turkish-Syrian border.

Russia has deemed the assassination a terrorist attack while John Kirby, a U.S. State Department spokesman, condemned the assassination as an “act of violence, whatever its source.”

Reuters notes that Melih Gokcek, mayor of the Turkish capital, said the attack was aimed at disrupting relations between Russia and Turkey.

Referring to the ISIS gesture “tawhid,” that the attacker Altintas reportedly used after the attack, Foreign Affairs has reported, “When ISIS militants hold up a single index finger on their right hands, they are alluding to the tawhid, the belief in the oneness of God and a key component of the Muslim religion.”

“As Salafi jihadists, members of the group adhere to a fundamentalist interpretation of tawhid that rejects non-fundamentalist regimes as idolatrous,” it added. “In other words, the concept of tawhid is central to ISIS’ violent and uncompromising posture toward its opponents, both in the Middle East and in the West.”