Turkey is beginning three days of mourning after two explosions at a peace rally in the capital Ankara killed at least 95 people, the deadliest such attack in the country's recent history.
The attack on Saturday also left 246 wounded, 48 of whom are in intensive care, according to an updated toll announced by Prime Minister Ahmet Davutoglu's office on Sunday.
The twin blasts, near Ankara's main train station, ratcheted up tensions ahead of Turkey's November 1 snap elections which were already soaring as the government wages an offensive on Kurdish fighters.
Bodies of slain demonstrators were seen strewn across the ground after the explosions, with the banners they had been holding for the "Work, Peace and Democracy" march lying next to them.
Turkey's pro-Kurdish Peoples' Democratic Party (HDP), one of the groups that called for the peace rally, put the death toll at 128 in a tweet from their official account, but this figure was not confirmed by the government.
President Recep Tayyip Erdogan denounced what he called a "heinous attack" targeting "our unity and our country's peace".
Declaring three days of mourning on Saturday, Turkish Prime Minister Ahmet Davutoglu said there were "strong signs" the attack was carried out by two suicide bombers.
International condemnation of the bloodshed was swift. German Chancellor Angela Merkel expressed "sadness and dismay" over the attacks, while US President Barack Obama and Russia's Vladimir Putin offered their condolences to Erdogan. Russian President Vladimir Putin said the attack was an "impudent act of terrorism".
Davutoglu said no one had claimed responsibility for the bombings but that groups including Islamic State of Iraq and the Levant (ISIL), the Kurdistan Workers' Party (PKK) and the far-left Revolutionary People's Liberation Party-Front (DHKP-C) were capable of carrying out such an attack.
Amateur footage filmed moments before the blasts and broadcast on local NTV television showed smiling activists holding hands and dancing before suddenly falling to the ground as a huge explosion went off behind them.
Reports said hundreds of people in Ankara rushed to hospitals to donate blood for the victims.
The death toll surpassed that of the May 2013 twin bombings in Reyhanli on the Syrian border that killed over 50 people.
HDP leader Selahattin Demirtas, blamed a "murderous state" for the deaths. "A barbaric attack has been committed," he said.
Among those killed was HDP member Kubra Meltem Mollaoglu, who was standing for parliament in the upcoming polls.
Turkey has experienced an upsurge in unrest in recent months, which began after over 30 people were killed in the predominantly Kurdish town of Suruc on July 20 in an attack against pro-HDP activists that was blamed on ISIL.
The outlawed PKK accused Ankara of collaborating with ISIL and resumed attacks on the security forces after observing a two-year ceasefire.
Over 140 members of the security forces have since been killed while Ankara claims to have killed more than 1,700 Kurdish fighters in weeks of bombardments of PKK targets in southeast Turkey and northern Iraq.
The PKK, which took up arms in 1984 demanding an independent state for Kurds, on Saturday announced it would suspend all offensive operations against Turkish forces ahead of the polls.
The HDP performed strongly in the last election in June, winning 80 seats in parliament to deprive Erdogan's ruling Justice and Development Party (AKP) of an outright majority for the first time since it came to power in 2002.
The AKP then failed to form a coalition in months of talks, prompting Erdogan -- who had been hoping for a large majority to push through reforms to boost his powers - to call fresh polls on November 1.