Scores of people gathered in the town of Reyhanli in Hatay province on Saturday after more than 40 people were killed in two car bombings that jolted the town earlier in the day.
A third explosion hit the Turkish town of Reyhanli near the border with Syria, hours after twin car bombs.
The demonstrators said the outbreak of violence was due to the Erdogan administration’s anti-Syria policy.
Turkey has been one of Syrian President Bashar al-Assad's harshest critics and has supported the foreign-backed militants fighting to topple his government.
Turkish opposition parties have censured the Turkish government for its intervention in Syria’s internal affairs.
A similar demonstration was briefly held in Ankara, in which dozens of people marched in the street and chanted slogans criticizing Erdogan and Foreign Minister Ahmet Davutoglu.