Tens of thousands of Turkish citizens flooded the streets on Monday denouncing the government for faulty security, mourning the 97 victims of Saturday's suicide bombings in capital Ankara.
In Istanbul, hundreds of protesters gathered in the metropolis' busiest Istiklal Street for a sit-in.
Demonstrators accused President Erdogan of his polarisation policy through inciting nationalism against the country's Kurdish minority, Xinhua reported.
"We know who the killer is," was written across one of the banners.
The ruling Justice and Development Party (AKP), founded by Erdogan, ended a peace process of two-and-a-half years with the outlawed Kurdistan Workers' Party (PKK) in July through renewed fighting.
"I impeach everyone in power over the deadly attack, the government, Tayyip, the presidential palace, everyone," said Cihat Parilti, a protester.
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A woman said she appealed to the government to restart peace negotiations with the Kurds. "This society suffered too much. We are not here to renew their suffering and shout," she said.
In Turkey's Aegean province of Izmir, thousands of people commemorated the Ankara bombing victims, however the scene quickly turned into an anti-government protest.
The twin blasts targeted a peace rally at Ankara's central railway station on Saturday, marking the country's worst ever terrorist attack on civilians, with scores of casualties in critical condition.
Erdogan condemned the "heinous" attack in a statement but is yet to address the public.
Turkey will again be voting on November 1, as Erdogan still hopes for a super AKP majority that can form a single-party government, a status held since November 2002 but lost in June's legislative elections.