[Source: Reuters]

Hamas leader Ismail Haniyeh was assassinated in the Iranian capital Tehran early on Wednesday morning, an attack that drew threats of revenge on Israel and fuelled further concern that the conflict in Gaza was turning into a wider Middle East war.

The Palestinian Islamist militant group and Iran’s Revolutionary Guards confirmed Haniyeh’s death. The Guards said it took place hours after he attended a swearing-in ceremony for Iran’s new president.

Although the strike on Haniyeh was widely assumed to have been carried out by Israel, Prime Minister Benjamin Netanyahu’s government made no claim of responsibility and said it would make no comment on the killing.

Haniyeh was killed by a missile that hit him “directly” in a state guesthouse where he was staying, Khalil Al-Hayya, a senior Hamas official, told a news conference in Tehran, quoting witnesses who were with Haniyeh. “Now we are waiting for the full investigation from the (Iranian) brothers,” Al-Hayya said.

Haniyeh, normally based in Qatar, had been the face of Hamas’s international diplomacy as the war set off by the Hamas-led attack on Israel on Oct. 7 has raged in Gaza. He had been taking part in internationally-brokered indirect talks on reaching a ceasefire in the Palestinian enclave.

The assassination occurred less than 24 hours after Israel claimed to have killed Hezbollah’s most senior military commander in the Lebanese capital Beirut in retaliation for a deadly rocket strike in the Israeli-occupied Golan Heights.

Two Lebanese security sources said on Wednesday that the body of Hezbollah operations chief Fuad Shukr had been found in the rubble of a building hit by an Israeli airstrike in Beirut’s southern suburbs.

Netanyahu made no mention of Haniyeh’s killing in a televised statement on Wednesday evening but said Israel had delivered crushing blows to Iran’s proxies of late, including Hamas and Hezbollah, and would respond forcefully to any attack.

The latest events appear to set back chances of any imminent ceasefire agreement in the nearly 10-month-old war in Gaza between Israel and the Iran-backed Hamas.

Hamas’ armed wing said in a statement Haniyeh’s killing would “take the battle to new dimensions and have major repercussions”. Vowing to retaliate, Iran declared three days of national mourning and said the U.S. bore responsibility because of its support for Israel.