At least 28 people have been killed and 61 injured after a car bomb targeted military vehicles close to government and military buildings in the Turkish capital, Ankara. Government spokesman Numan Kurtulmus confirmed the rising death toll and said that responsibility for the blast is yet to be claimed.
A car laden with explosives was detonated near the Turkish General Staff headquarters, the Prime Ministry, Parliament and Defence Ministry. The blasts hit a convoy of vehicles carrying military personnel. Some civilians are reported to be amongst the dead. Kurtulmus, who is also a deputy prime minister, said it was clear the attack was well-planned.
In a statement released several hours after the attack, President Recep Tayyip Erdogan said Turkey was more determined than ever to use "its right to self-defence". He said: "Our determination to respond in kind to attacks taking place inside and outside our borders is getting stronger with such acts". Deputy Prime Minister Bekir Bozdag called it an "act of terrorism".
A Turkish security source told Reuters that the bombing was likely to have been committed by Kurdish separatist group PKK, however sources in Turkey's mainly Kurdish southeast said they believed that the Islamic State (Isis) was responsible.
State watchdog RTUK has banned all broadcast reporting on the blast in the city. Pictures shared by Twitter users show a plume of smoke rising into the night sky, with the explosion audible throughout the city.
"I heard a huge explosion. There was smoke and a really strong smell even though we were blocks away," a witness told Reuters.
European leaders and government officials reacted with outrage to the attack. Chancellor Angela Merkel was among the first to condemn the attack and expressed Germany's support to Turkey in the fight against terrorism. "The Federal German government strongly condemns this recent terror attack," Merkel said in a statement. "I would like to tell the Turkish people the following: We Germans are sharing your pain. We will stand side-by-side Turkey in fighting those who are responsible for such inhuman acts," she added.
NATO secretary-general Jens Stoltenberg said Turkey had the alliance's full backing after the atrocity. He said in a statement: "I offer my deepest condolences to the families of those killed and to the Turkish people. My thoughts are also with those who have been wounded. There can be no justification for such horrific acts. NATO Allies stand shoulder to shoulder in the fight against terrorism."
Federica Mogherini, the EU's High Representative for Foreign Affairs, offered solidarity on behalf of Europe. "Another terrible attack hit the center of Ankara tonight. The EU extends condolences to the families of the victims killed in the attack and wishes a speedy recovery to those injured. Our fullest sympathy goes to the Turkish people and authorities. We are with Turkey and its people in these difficult times and stand by all those who suffer from the consequences of such violence, and of terrorism."
In a statement issued from the Elysee Palace, French President Francois Hollande denounced the "horrific attack" in Ankara, expressing solidarity with the Turkish people.
Pakistan's Foreign Ministry also condemned the terrorist attack in Ankara and reaffirmed its solidarity with Turkey. "We have no doubt that Turkey would eliminate the scourge of terrorism with its strong will and unshakable resolve," a statement read.
The US Department of State Counterterrorism Bureau tweeted: "The US strongly condemns the terrorist attack on Turkish military personnel & civilians today in #Ankara,#Turkey.@StateDept @USEmbassyTurkey".
UK foreign secretary Philip Hammond said: "My thoughts are with the victims of #Ankara terror attack. The UK utterly condemns this senseless act of violence."
Central Ankara is on lockdown following the deadly blast, with police blocking roads into the city.
Turkish Prime Minister Ahmet Davutoglu said authorities were investigating the incident. He said: "We have received information and we are looking into it." In the wake of the blast he has cancelled an official trip to Brussels where he was due to take part in a mini-summit on the refugee crisis in Europe. Erdogan also cancelled a trip to Azerbaijan.
The latest attack on Ankara comes as Turkey steps up its involvement in the conflict in neighbouring Syria. It has been shelling the Kurdish YPG militia in northern Syria, who it sees as allied to the PKK. Turkey has also allowed the coalition bombing IS to use one of its air bases.