According to Iranian reports, Haniya was killed in an air strike. A robot fired from another country is said to have hit his residence at 02:00 local time. He was in the country for the installation of Iran's new president and lived in a residence for war veterans.
Hamas confirms the death, and states in a statement that Haniya died in an "attack by Zionists". The extremist Palestinian movement promises revenge.
Several countries, including Iran, Qatar, and Turkey, condemn the attack, which they call "cowardly". Iran promises to "punish Israel severely".
The attacks in Tehran and Beirut do not improve the tense regional situation, according to a statement from the White House in the USA. However, the White House does not see a direct increased risk of escalation.
"The Axis of Evil"
Israel's Prime Minister Benjamin Netanyahu said in a live broadcast on Wednesday evening from Tel Aviv that "Israel is ready for all scenarios" and confirms that Israel's military IDF is behind the attack on Hezbollah's commander Fuad Shukr in Beirut, Lebanon.
He did not specifically mention the attack on Hamas leader Ismail Haniya in Iran's capital Tehran, but only stated that Israel will continue to fight the "country's enemies".
We have struck at the axis of evil, said Netanyahu in the brief statement.
Shortly afterwards, Hezbollah confirmed that commander Fuad Shukr had been killed in the attack.
Under Investigation
Ismail Haniya, who has had his base in Qatar for several years, participated on Tuesday when Iran's new president Masoud Pezeshkian took office. Iran did not provide immediate details on how Haniya was killed, but according to the Revolutionary Guard, the attack is under investigation.
Ismail Haniya has been the chairman of Hamas' highest decision-making body, the so-called politburo with 15 members, since 2017 and has since become a face internationally.
The 62-year-old was born in an established refugee camp on the Gaza Strip, near Gaza City, and joined Hamas in the late 1980s.
He left Gaza in 2019 and has since then, except for a short period in Turkey, been based in Qatar's capital Doha.
Accuses Israel
Israel has previously stated that those responsible within Hamas will be killed, following the group's terrorist attack on Israel last autumn.
Since Hamas' terrorist attack on Israel on October 7 – when 1,200 people were killed and 250 were taken hostage – up to 40,000 Palestinians have been killed in Israeli attacks in Gaza, according to the Hamas-controlled health department.