Who is the Kurdish group behind Istanbul's deadly attack?

The group, an offshoot of the Kurdistan Workers Party (PKK), said in a statement that the bombing had been carried out as retribution for ongoing violence in southeast Turkey where the Turkish army has fought with Kurdish rebels, in addition to the continued imprisonment of PKK leader Abdullah Ocalan.

The PKK has led a guerrilla insurrection against the Turkish state calling for greater autonomy for Kurds in Turkey since the 1980s.

A peace deal between the PKK and the Turkish state, that had lasted tentatively for two years, collapsed last summer, leading to an escalation of violent conflict.

TAK first appeared in August 2004 when the group claimed responsibility for two Istanbul hotel bombings, and has carried out numerous violent attacks in Turkey since then.

In contrast to the PKK, TAK has called for an independent Kurdish state, and the PKK has notably denounced certain TAK attacks in the past. 

A post on TAK’s website defines the group distinctly from the PKK stating:

“For a period, we were inside the PKK and fought the enemy together. We then decided the methods of struggle … were too feeble. That is why we left the organization ... and set up the TAK.”

However, although analysts differ on the precise nature of the relationship between the PKK and TAK, in the eyes of the Turkish state, both groups along with the Syrian Kurdish People’s Protection Units (YPG) are viewed as essentially the same.

Notable TAK attacks this year

Before Saturday’s Istanbul bombing TAK militants had already carried out at least four significant attacks in Turkey this year:

1) 17 February — 8 people are killed in TAK attack on convoy carrying military personnel in Ankara.

2) 13 March — 37 people are killed in TAK suicide bombing in Istanbul’s central Kizilay district.

3) 7 June — TAK bomb attack once again targeting police convoy in Istanbul’s Veznecirel district kills seven police officers and four civilians. 

4) 6 November — TAK claim bomb attack in southeastern city of Diyarbakir that leaves 11 dead. 

5) 10 December — 38 people killed in TAK attack outside Istanbul's Vodafone arena. 

Speaking on Sunday Turkish President Recep Tayyip Erdogan vowed to "fight terrorism to the end" [Getty]

Other attacks have been carried out by the PKK this year such as a 9 October bomb attack on a military checkpoint in southeast Turkey that killed 10 soldiers and eight civilians. 

In addition to attacks carried out by TAK and other Kurdish groups, Islamic State group militants have also carried out a number of deadly attacks.

Speaking at a funeral for some of the policemen killed in Saturday’s attack, Turkish President Recep Tayyib Erdogan vowed to “fight terrorism to the end” with Turkish state-affiliated media outlet Anadolu reporting that Turkish airstrikes had targeted PKK positions in northern Iraq.

According to Ankara, since the truce between the PKK and the Turkish state collapsed last year 300 civilians and 800 security personnel have been killed in addition to 8,000 Kurdish militants.