ISTANBUL: A Kurdish militant group on Thursday claimed responsibility for a suicide car-bomb attack in the Turkish capital which killed 37 people.

In a statement posted on its website, the Kurdistan Freedom Falcons said the attack in Ankara was in "revenge" for Turkish military operations against Kurdish rebels in the southeast.

"We claim the operation of March 13, 2016 at 6:45 p.m. in the heart of the Republic of Turkey," the statement said.

The group said the attack was led by Seher Cagla Demir, code name Doga Jiyan, described as the first female suicide bomber in its ranks.

The name corresponds with the findings of Turkey's Interior Ministry, which on Tuesday had identified the suicide car bomber as a 24-year-old woman who became a Kurdish rebel in 2013 and had trained in Syria.

The Turkey-based Freedom Falcons group is considered an offshoot of the Kurdistan Workers' Party, or PKK, and has carried out several attacks in the past including one in Ankara in February that killed 29 people.

Germany on Thursday closed its embassy in Ankara, the German school in Ankara and the consulate in Istanbul following a security warning.

Foreign Minister Frank-Walter Steinmeier told reporters in Berlin that there were "some very concrete indications that terrorist attacks were being prepared against our facilities in Turkey." He did not say how long the facilities would be closed.

Germany, which has a large and long-standing ethnic Turkish population, has been a driving force behind a deal between the EU and Turkey to manage Europe's migration crisis. Germany contributed Tornado reconnaissance jets, tanker aircraft and a frigate to the Western coalition battling the so-called Islamic State group.

More than 200 people have died in five suicide bombings in Turkey since July that were blamed on the Kurdish rebels or the Islamic State group.

The Kurdistan Freedom Falcons, also known as TAK, warned that there would be further reprisals for any "hostile operations against the Kurdish people" or jailed PKK leader Abdullah Ocalan.

Since August, Turkey has carried out military operations and imposed 24-hour curfews in flashpoint districts where militants have set up barricades, dug trenches and planted explosives to keep the authorities at bay.

A curfew was lifted Wednesday in parts of the mainly Kurdish city of Diyarbakir, according to a statement by local administrators. Operations continued elsewhere in the southeast, with 40 people detained Thursday, according to the state-run Anadolu Agency.

The military operations have displaced tens of thousands of people, caused vast damage to urban infrastructure and raised concerns over possible human rights abuses. The decades-long conflict between the Turkish state and Kurdish rebels has claimed 40,000 lives.

In response to surging violence, President Recep Tayyip Erdogan wants to redefine the terms "terror" and "terrorist" so that their legal scope can expand to anyone — including legislators, academics, journalists or activists — suspected of supporting terrorism.