The Russian flag flies over the Embassy of Russia in Washington, U.S., August 6, 2018. REUTERS/Brian Snyder

MOSCOW (Reuters) - Russian President Vladimir Putin expressed condolences to Iran’s president on Saturday after an attack on an Iranian military parade, saying Moscow was ready to boost joint efforts in the fight against terrorism, RIA news quoted the Kremlin as saying.

Gunmen fired on a viewing stand at the parade in southwest Iran on Saturday and killed 24 people, half of them members of the Revolutionary Guards, state news agencies reported, in one of the worst attacks ever on the elite force.