A radical Kurdish group with ties to the outlawed Kurdistan Workers' Party (PKK) on Thursday claimed the deadly suicide car bomb attack that killed 35 people in Ankara last weekend.

The claim by the Kurdistan Freedom Falcons (TAK) came as Germany closed diplomatic missions and a school in Turkey Thursday over security concerns.

In a statement on its website, TAK named the woman bomber as Seher Cagla Demir, who had been involved since 2013 in a "radical fight against a policy of massacre and denial against the Kurdish people."

"On the evening of March 13, a suicide attack was carried out... in Ankara, the heart of the fascist Turkish republic. We claim this attack targeting centres... where decisions to massacre Kurdish people are made," the statement said.

The group said it was a response to security operations by Turkish forces in the Kurdish-dominated southeast of the country.

"This action was carried out to avenge the 300 Kurds killed in Cizre as well as our civilians who were wounded," the statement said.

"We would like to apologise for the civilian losses which had nothing to do with the dirty war being waged by the fascist Turkish republic," the group added.

In February, Turkish forces ended an almost two-month military offensive backed by a curfew against Kurdish rebels in the southeastern town of Cizre.
- Tightened security -

Turkey has suffered five major bombings since July last year, killing more than 200 people, including two in Ankara in less than a month.

Foreign missions in the capital have heightened security measures.

The German embassy in Ankara as well as the consulate and German school in Istanbul were closed Thursday for security reasons, the consulate said on its website.

Last January, 12 German tourists were killed in a suicide attack blamed on the Islamic State group in the heart of Istanbul's tourist district.

Turkey, which faces multiple security threats, is battling both IS and Kurdish militants.

Sunday's attack came three weeks after a similar car bombing in Ankara killed 29 people, also claimed by TAK.

In the immediate aftermath of the latest bombing, the Turkish authorities pointed the finger at the Kurdistan Workers Party (PKK), against which Ankara has waged a relentless assault since late last year after a shaky two-year truce collapsed.

The government said one of the bombers was a woman in her mid-20s affiliated with the PKK and trained in Syria by the People's Protection Units (YPG), a Kurdish militia group the Turkish military shelled for several days in February.

The TAK statement on Thursday included a photo of the woman bomber.

The TAK is a little-known group which has nonetheless risen to prominence in recent months after the February bombing and after it claimed a mortar attack on Istanbul's Sabiha Gokcen airport on December 23.

The shelling left one airport cleaner dead and also damaged several planes.

The PKK launched a bloody insurgency against the Turkish state in 1984 for greater autonomy for Kurds, a conflict that has claimed some 40,000 lives and is listed as a terror group by Ankara and its Western allies.

Authorities detained 11 people over Sunday's attack, Prime Minister Ahmet Davutoglu said, while Turkish jets bombed PKK targets in northern Iraq just hours after the blast.