Thousands of people have gathered in the centre of Turkey's capital, Ankara, to mourn the victims of twin bomb blasts which killed at least 95 people.
Scuffles broke out with the police after some mourners tried to lay flowers at the sites where the bombs went off on Saturday.
A pro-Kurdish party involved in the rally where the bombs went off believes the true death toll is 128.
Security sources say they suspect Islamic State (IS) bombed the rally.
The government has furiously denied suggestions it was involved in the attacks itself.
The blasts took place near Ankara's central train station as people gathered for a march organised by leftist groups demanding an end to the violence between the Turkish government and Kurdish separatist PKK militants.
In an expected announcement, the PKK declared a unilateral ceasefire on Saturday, calling on its fighters to halt its guerrilla activities in Turkey except in cases of self-defence.
However, on Sunday the Turkish military said it had carried out air strikes against the group, attacking targets in south-eastern Turkey as well as PKK positions in northern Iraq, and killing 49 people.
At the scene: Selin Girit, BBC News, Ankara
On Sunday, thousands of people had gathered at the square in central Ankara where a peace rally had been due to take place before it was interrupted by violence.
There was a clear sense of anger towards the government, with people blaming it for security failures.
The bombing comes at a very significant and tense time. Funerals have become a routine event and even before Saturday's blasts, emotions were running high across the country.
Now people are concerned about a further escalation in violence and maintaining security at elections in three weeks' time.
Sunday saw the start of three days of mourning for the victims.
In Istanbul, hundreds of mourners at the funeral of one victim, Kubra Meltem Mollaoglu, chanted "The killer government will be held accountable for its crimes!"
They carried a placard which read, "She wanted peace, she was killed."
No group has said it carried out the attacks.
Prime Minister Ahmet Davutoglu said there was evidence two suicide bombers had been involved.
He suggested either IS or the PKK could be behind the attacks but two senior Turkish security officials who spoke to Reuters news agency said the initial signs were that IS was to blame.
"All signs indicate that the attack may have been carried out by Isil [IS]," one of the unnamed sources said. "We are completely focused on ISIL."
Terrorism experts have said the attack is similar to one that was carried out in Suruc in southern Turkey by IS in July in which 30 people died.
The Suric attack led to the collapse of an earlier ceasefire between the PKK and the government, with the PKK accusing the security forces of collaborating with IS.
However, the leader of the pro-Kurdish HDP party blamed the state and cancelled all rallies ahead of the early general election next month.
A HDP rally in the city of Diyarbakir was bombed in June, ahead of the earlier general election, in which the party entered parliament for the first time.
Cemalettin Hasimi, director of press and information at the prime minister's office, told the BBC that such allegations were "a disgrace, unacceptable".
Turkey is mourning the deaths of at least 95 people. These just a few of those who lost their lives, clockwise from top left:
- Elif Kanlioglu: A 20-year old student in her second year of university, who loved studying foreign languages.
- Yilmaz Elmascan: Described by a friend as a peace-loving man, who got married last year. His wife is also said to have been killed in the attack.
- Sebnem Yurtman: Studied at Ankara university, and later was a student in Adana, and was described as "full of life".
- Mesut Mak: He was a member of an agriculture and forestry union. He had a daughter.