Syrian social media users have reacted with alarm after the Syrian Democratic Forces (SDF) unveiled a large picture of Kurdistan Workers' Party (PKK) leader Abdullah Ocalan in the centre of Raqqa following the city's liberation from the Islamic State (IS) group.

The US-backed SDF, which is composed of Arabs and Kurds, took control of Raqqa this week. The portrait of Ocalan was raised in the central al-Naim square by fighters affiliated to the People's Protection Units (YPG) during a parade of the female-only Women's Protection Units (YPJ):

In a statement after the flag-raising, the YPJ command said the victory in Raqqa was a victory for both Ocalan and women against the IS and other Islamist groups in Syria.

“Women have freed themselves of the exploitative male regime in political, social, cultural and military aspects, and became a solution to the problems and builder of morals," said Nesrin Abdullah.

"The establishment of women’s army against Ahrar al-Sham, Nusra and ISIS was a response to the powers in Syria, and a major step serving for the peoples of Syria.”

She ended the statement with the slogan “Jin, Jiyan, Azadi” translating as "woman, life, freedom".

Ocalan, who was born in the Turkish province of Sanliurfa, was a co-founder of the PKK in 1978 and led a guerrilla war against the Turkish state that resulted in more than 40,000 deaths.

Although the YPG has claimed it is independent from the PKK, the group acknowledges Ocalan as its ideological figurehead and PKK commanders are thought to control key institutions in northern Syria.

Syrian opposition activists criticised the move on Twitter with some saying that one "terrorist" group, the Islamic State group, had simply been traded in for another:

US has stated it supports YPG, not PKK. Thus, the image of PKK's head, Abdullah Ocalan, in Raqqa's town square today is dedicated to the US. pic.twitter.com/XbBxrJ0LZU — هادي العبدالله Hadi (@HadiAlabdallah) October 19, 2017

#Raqqa city:: AlBagdadi photo has been replaced with Abdullah Ocalan the leader of #PKK which consider internationally a terrorist group pic.twitter.com/ueWIr8NnaG — Hussam Eesa (@HussamEesa) October 19, 2017

The US has supported the YPG as part of the SDF in its fight against IS, but at the same time regards the PKK as a terrorist organisation, as do the UK and EU.

Turkey has repeatedly criticised the US for supporting the YPG, who it says are indistinguishable from the PKK.

IS captured mostly Sunni Arab Raqqa in 2014, and under its rule the city became infamous for gruesome abuses and a planning centre for attacks abroad.

Victory Dance by the free men & women of YPG/YPJ/SDF. After 134 days of fighting day & night & support from @coalition #SDFfreedRaqqa ✌️ pic.twitter.com/gJ0Aq8wZpo — Rojava (@AzadiRojava) October 19, 2017

Its loss deals a major blow to the militants' dreams of statehood, and comes after their July defeat in Iraq's second city Mosul, their other major urban stronghold.

In Syria, they are now confined largely to Deir Ezzor province, where they are under attack by both the SDF and Russian-backed government forces.

In neighbouring Iraq, they hold only a small stretch of the Euphrates valley adjoining the Syrian border, a far cry from their peak in 2014, when their "caliphate" was approximately the size of Britain.