TEHRAN/GAZA -- Hamas Politburo Chief Ismail Haniyeh and one of his bodyguards have been killed in the Iranian capital of Tehran, Iran's Islamic Revolution Guards Corps (IRGC) said on Wednesday.

Haniyeh and his bodyguard were killed early Wednesday when their residence was hit in Tehran, according to a statement published on the IRGC's official news outlet Sepah News.

The statement said the attack was under investigation and the results would be announced later.

The Islamic Hamas movement confirmed the death of its leader, saying Haniyeh was assassinated by an Israeli attack in Iran.

In a press statement, Hamas said that it "mourns to the Palestinian people, the Arab and Islamic nation, and the free people of the world," after their leader Ismail Haniyeh was killed in an Israeli raid on his residence in Tehran.

Haniyeh was in Tehran to attend the swearing-in ceremony of Iranian President Masoud Pezeshkian on Tuesday.

He was also expected to discuss with the Iranian president the political and field developments related to the Palestine-Isreal conflict in the Gaza Strip, a source close to Hamas told Xinhua.

The Israeli army has no comment on the issue yet.

Since Oct. 7 last year, Israel has been launching a large-scale strike on Hamas.

According to Gaza health authorities, the Israeli offensive has led to the killing of over 38,000 Palestinians in the enclave, while the UN estimated that nearly 2 million people there have been displaced.