Tehran, Aug 10 (IANS): A top Iranian military commander said Tehran considered avenging the assassination of Hamas Politburo Chief Ismail Haniyeh as its duty, Iranian media has reported.

Esmaeil Qa'ani, commander of the Quds Force of Iran's Islamic Revolution Guards Corps, made the remarks in a letter congratulating Yahya Sinwar on his appointment as Hamas politburo chief and extending condolences for Haniyeh's death, official news agency IRNA reported on Friday.

"We consider it our duty to avenge the blood of Haniyeh," who was killed in a "bitter" incident in Iran, Qa'ani noted.

Qa'ani said the "heroic struggle" of the resistance groups would further intensify the impact of the punishment, Xinhua news agency reported, citing IRNA.

Hamas announced on Tuesday that Sinwar, the group's leader in the Gaza Strip since 2017, would succeed the late chief Ismail Haniyeh, who was assassinated in Tehran last week.

Sinwar, 61, has spent more than 20 years in Israeli prisons before being released in a 2011 prisoner exchange deal with Israel. He is considered by Israel as one of the principal planners of the October 7, 2023, attack on Israel.

Haniyeh, who had been invited to attend Iranian President Masoud Pezeshkian's swearing-in ceremony on July 30, was killed along with his bodyguard the following day when their residence in Tehran was hit. Iran accused Israel of carrying out the attack and vowed "a harsh and painful response."