"Turkey's patience and composure are being tested," Recep Tayyip Erdogan said in nationally broadcast remarks at a Mother's Day rally in Istanbul.
"They want to drag Turkey into a filthy scenario. But we will not fall into this trap," he said.
"Today, we have to be one.
"The purpose of these attacks is to give opportunities to those who collaborate with the Baath regime," he said, referring to Syria's ruling Baath Party led by President Bashar Assad.
"These are attacks intending to provoke those who live in peace, especially in the Hatay [province]," said Erdogan, who is scheduled to meet with U.S. President Barack Obama in Washington Thursday. They are widely expected to discuss Syria.
Saturday's massive twin bombings, which killed at least 46 people and injured at least 155, occurred in the southern Mediterranean Hatay province border town of Reyhanli, sharply escalating tensions between the former allied neighbors.
Turkey said Sunday they arrested nine Turkish citizens in the bombings and alleged the group was backed by Syrian intelligence services.
"This incident was carried out by an organization ... which is in close contact to pro-regime groups in Syria, and I say this very clearly, with the Syrian mukhabarat," Interior Minister Muammer Guler told reporters in remarks broadcast by Turkish Radio and Television.
"Mukhabarat" is the Arabic term for intelligence, as in a spy agency. Syria has three intelligence agencies, with the most influential the General Security Directorate, under the Interior Ministry, and the Military Intelligence Directorate, controlled directly by Assad.
Guler did not say which Syrian intelligence agency Turkey believed the nine arrested Turks are linked.
Syrian Information Minister Omran al-Zoubi denied any Syrian involvement.
"Syria didn't and would never undertake such acts because our values don't allow us to do this," he said in remarks broadcast by Syrian state media.
"It is Erdogan who should be asked about this act. He and his party bear direct responsibility," Zoubi said, suggesting Erdogan may have been behind the attack to persuade Washington to intervene in Syria when he meets with Obama.
Ankara had no immediate comment.
Erdogan told the Istanbul rally people in Turkey must not retaliate against Syrian refugees for the bombings, saying this would only serve the interests of the bombers.
"If there is a single attack against a Syrian guest, even only verbal, the attackers will win," he said.
But Erdogan vowed, "Those who attack Turkey will be held to account, sooner or later."
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