World leaders have condemned a terror attack in central Turkey's Kayseri province that martyred at least 13 soldiers and wounded 56 others.
The Turkish General Staff said in a statement the car bomb targeted a public bus carrying off-duty troops near the Erciyes University campus at 8.45 a.m. local time (0545 GMT).
Speaking to the private news channel NTV in Istanbul, Deputy Prime Minister Numan Kurtulmus said all signs pointed towards the involvement of the PKK terrorist group.
Head of the Pakistan's foreign affairs ministry, Sartaj Aziz condemned terrorist attack in "strongest" terms.
"We condemn in the strongest possible terms the terrorist attack that took place in Kayseri today," said Aziz.
Aziz extended condolences to the government and Turkish people "on behalf of the Prime Minister, the government and the people of Pakistan".
"We reiterate our unwavering solidarity with Turkey and reaffirms strong belief that the brotherly people of Turkey would be successful in their resolute fight against the scourge of terrorism," Aziz added.
President Vladimir Putin conveyed condolences to President Recep Tayyip Erdogan and said Russia was "ready" to cooperate with Ankara in fighting against terrorism, Kremlin press service said.
Russian Foreign Minister Sergey Lavrov also talked to his Turkish counterpart Mevlut Cavusoglu on the phone following the attack and conveyed his condolences.
In a statement, Azerbaijani President Ilham Aliyev condemned "bloody incident" and said: "We support you in fighting terrorism that turns into a terrible calamity. We always stand by brotherly Turkey.”
The United States condemned the "cowardly attack".
"We stand united with Turkey, our NATO Ally, in our determination to confront and defeat all forms of terrorism," White House National Security Council spokesman Ned Price said in a statement.
The State Department spokesman said the U.S. administration is ready to provide support.
“There is absolutely no justification for inhumane acts perpetrated against the Turkish people by terrorists,” John Kirby said. “We are in close touch with Turkish authorities and have offered our support to the ongoing investigation of this attack.”
Canadian Foreign Minister Stephane Dion wrote on Twitter: "I condemn the attack in #Kayseri and offer my condolences to the families and friends of the victims."
Italian Foreign Minister Angelino Alfano condemned the bloody attack and expressed solidarity in the wake of the deadly attack, according to his official Twitter account.
Germany has denounced the terror attack and voiced solidarity with Turkey in the fight against terrorism.
“Nothing can justify this perfidious violence," German Foreign Ministry said in a press release on Saturday. “We share the grief, stand in solidarity with Turkey,” the statement said.
Germany’s EU minister Michael Roth expressed condolences and sympathies to the families and relatives of the victims.
In his Twitter account, Roth said: "I condemn the horrific terror attack in Kayseri. My thoughts are with the victims and their families. What Turkey really needs is peace."
France also expressed condemnation and voiced support for Turkey's fighting against terrorism.
"We offer our condolences to the families of the victims and their families," Jean-Marc Ayrault, the French foreign minister said in a written statement.
"We express our solidarity with Turkey in the fight against terrorism."
In a written statement, Thorbjorn Jagland, the secretary-general of the Council of Europe, said terrorist attacks must stop. "They lead only to human suffering and serve no political goal.”
“The Council of Europe stands by Turkey and its people in these difficult times,” Jagland added.
On his Twitter account, Ukraine's President Petro Poroshenko posted: "Condemn a terrorist attack in Kayseri. Condolences to families of victims. We stand by Turkey. Terrorism is unjustifiable."
Ditmir Bushati, foreign minister of Albania, said he strongly condemned "violence & share the grief of people Turkey."
Austrian foreign minister Sebastian Kurz said: "My heartfelt condolences for the victims of the bomb attack in Kayseri. We strongly condemn such acts of terror!"
Minister of Public Administration of Kosovo, Mahir Yagcilar said the treacherous attacks would not reach the treacherous purposes. "I strongly condemn the attack in Kayseri. I curse terror," Yagcilar said on Twitter.
In a written statement, Spain's foreign affairs ministry said: "Spain shares the pain of the families of the victims, the people and the Turkish authorities in these difficult times and wishes the prompt and total healing of the wounded."
"The Government reiterates its sincere solidarity with Turkey in the fight against terrorism and its conviction is that the actions of the security and justice forces and close international cooperation will put an end to this scourge."
High Representative for Foreign Affairs and Security Policy of the European Union Federica Mogherini, Norwegian Foreign Minister Borge Brende and Italian Foreign Minister Angelino Alfano phoned phoned Cavusoglu and condemned the attack, according to diplomatic sources.
Kuwait also condemned the blast as a terrorist act that targeted innocents. Emir of Kuwait Jaber Al Ahmad Al Sabah Kuwait sent his condolence to Erdogan.
Saudi Arabia, Qatar and Egypt also condemned the attack, expressing solidarity with Turkey.
Saudi Arabia’s foreign ministry also said that Saturday's terror attack was “unacceptable”.
In an official statement, Egypt's foreign ministry spokesman Ahmed Abu Zeid reiterated Egypt's stance against the terrorism.
Qatar also "strongly" condemned and in a statement, the Ministry of Foreign Affairs expressed Qatar's solidarity with Turkey in all measures it takes to maintain its security and stability.
The PKK -- listed as a terrorist organization by Turkey, the U.S. and the EU -- resumed its decades-old armed campaign in July last year.
More than 300 civilians and about 850 security personnel since have been martyred. More than 9,000 PKK terrorists have been killed or apprehended.