JERUSALEM (JTA) — Israeli Prime Minister Benjamin Netanyahu and President Shimon Peres sent condolence letters to Russian President Vladimir Putin following two terror attacks in Volgograd.

The suicide bomb attacks on Sunday in the city’s main rail station and on Monday on a public bus have left at least 31 dead and dozens wounded.

Netanyahu expressed “deepest sympathies” to the families of those killed in the letter sent Monday. “These despicable attacks serve as a painful reminder of the urgent need for all peace-seeking nations to join forces in a united and concerted effort to eradicate the dangerous scourge of terrorism. I have no doubt that the citizens of Volgograd will continue to demonstrate the resilience, resolve and courage for which their city is renowned,” Netanyahu wrote.

“My heart goes out to those who have been affected by previous attacks which have recently afflicted Russia. I cannot but strongly condemn attacks on innocent people by terrorists who are driven by hate and a thirst for destruction,” Peres wrote following the attack Sunday on the rail way station. “Terrorism is the cause of much senseless pain and suffering in the world, and I trust that the international community will continue to unite in a fight to eliminate this terrible scourge and encourage peace and security to all.”

Police believe the two bombings were linked, since they were both packed with the same kind of shrapnel, according to Reuters. There has been no claim of responsibility.

The attacks are seen as a threat on the upcoming Winter Olympics, which are set to be held in Sochi, located on the Black Sea, about 450 miles southwest of Volgograd. The Olympics begin on Feb. 7. Putin has ordered security stepped up throughout the country.

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