Turkey begins three days of mourning on October 11 after at least 95 people were killed in twin blasts at a peace rally in the capital, Ankara.
The Turkish government said 245 people were also injured in what it called a "terrorist act," with 48 of them in serious condition.
Scuffles broke out in Ankara on October 11 after police prevented pro-Kurdish politicians and other mourners from placing flowers at the site of the blasts.
The co-leaders of the pro-Kurdish Peoples' Democratic Party (HDP), Selahattin Demirtas and Figen Yuksekdag, were planning to hold a memorial for the victims but police held them back insisting investigators were working at the site.
Prime Minister Ahmet Davutoglu said there were "strong signs" that suicide bombers carried out the October 10 attack, which came three weeks before a rerun of June's inconclusive general elections.
The explosions, which struck 50 meters apart, occurred near the city's central train station as people were gathering for a planned "peace march" to push for a settlement of the conflict between the government and Kurdish militants in the southeastern part of the country.
The march, which has been cancelled, was organized by pro-Kurdish and leftist political parties.
Police reportedly fired warning shots into the air to disperse angry crowds at the scene of the blasts.
Thousands of protesters later gathered in Istanbul, chanting antigovernment slogans and blaming the government for the Ankara bomb attacks.
Turkey's pro-Kurdish Peoples' Democratic Party (HDP) was one of the groups that called for the peace rally. Its leader, Selahattin Demirtas, blamed the state for what he called an attack “against the people.”
Explosions at an HDP rally in the southeastern city of Diyarbakir killed two people in June, ahead of general elections in which the party entered parliament for the first time.
President Recep Tayyip Erdogan denounced what he called a "heinous attack" targeting "our unity and our country's peace."
The president cancelled a planned official visit to Turkmenistan after the bombings. He had been due to attend a summit with the heads of state of Azerbaijan and Turkmenistan on October 12.
Davutoglu, the prime minister, said no one claimed responsibility for the bombings, but cited the Islamic State (IS) group, the Kurdistan Workers' Party (PKK), and the far-left Revolutionary People's Liberation Party-Front (DHKP-C) as potential suspects.
U.S. President Barack Obama spoke to his Turkish counterpart and "conveyed his deepest personal sympathies for those killed and injured in these heinous attacks," the White House said.
The Anadolu Agency, citing unnamed officials, reported that Obama said the United States would continue to side with Turkey in the fight against terrorism.
Russian President Vladimir Putin telegraphed his condolences to Erdogan, the Kremlin said. Putin expressed Russia's willingness "to work together with the Turkish authorities as closely as possible in opposing the terrorist threat," according to the statement.
Russia's Foreign Ministry said the attack "confirms the need to consolidate the efforts of all regional and extraregional partners in combatting terror."
In July, a suicide bombing by suspected IS militants killed at least 30 people in the Turkish town of Suruc on the Syrian border. The attack targeted a cultural center as a Kurdish political group was conducting a press conference.
A truce between the PKK and Turkey's government later broke down, with the Kurdish militant group accusing the security forces of collaborating with the IS group.
This led to an increase in attacks from both sides.
But on October 11, the PKK declared a halt to guerrilla activities in Turkey, saying its fighters would avoid actions that could prevent "fair and just" elections on November 1.
The statement from an umbrella group that includes the PKK did not mention the bombing in Ankara.
The announcement had been anticipated earlier in the week when a top PKK commander wrote a newspaper column floating the idea.
Turkish Deputy Prime Minister Yalcin Akdogan has dismissed the idea as a mere "tactic" to boost support for the HDP.