On Friday, a gunman shot and killed seven people and injured several more outside a synagogue in East Jerusalem. According to the preliminary findings of the Israeli police, the attack was a "terrorist incident."
The attacker was shot dead by police as he tried to flee the crime scene.
"The unspeakable cruelty inflicted on the innocents praying today in the House of God in Neve Yakov, Israel," Zbigniew Rau wrote on Twitter on Friday night.
"I strongly condemn this barbaric act of terrorism and join in the suffering with the families of the victims. May the Merciful Lord soothe their pain," he added.
No radical has organisation claimed responsibility for the attack, but Palestinian Hamas said it was a response to Thursday's attack by Israeli forces on the Jenin refugee camp in the West Bank. (PAP)