Story highlights Bomber who killed four in Istanbul on Saturday had connections to ISIS, says interior minister

Three of the dead were Israelis, two of whom had dual American citizenship

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Istanbul, Turkey (CNN) A suicide bomber who struck a busy tourist area in central Istanbul on Saturday, killing at least four people, was a Turkish citizen with links to ISIS, Turkey's Interior Minister Efkan Ala said Sunday.

Speaking to reporters in Istanbul, Ala identified the attacker as Mehmet Ozturk, who was born in 1992 and registered in Gaziantep, a city in southern Turkey, near the Syrian border.

"The evidence at hand shows that he is connected to the Daesh terrorist organization," said Ala, using another name for ISIS.

"We are still considering with great sensitivity other connections or forces behind this. The fight against terror will continue."

He said that security forces had said there had been no previous warrants issued for the bomber. Five others had been detained in relation to the attack, he said.

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