The bomb that killed Ismail Haniyeh, the top leader of Hamas, in Iran early Wednesday was planted several weeks ago, according to a new report.

Haniyeh traveled to Tehran to attend the inauguration ceremony of Iran’s new president, Masoud Pezeshkian, and had been seen at the event in the hours before the attack.

Sources told The New York Times that assassins planted the explosive roughly two months ago in a Tehran guesthouse protected by the Islamic Revolutionary Guards Corps where Haniyeh had stayed before.

Breaking News: Ismail Haniyeh, the Hamas leader assassinated in Iran this week, was killed by a bomb smuggled into his guesthouse months ago, Middle Eastern officials said. https://t.co/O8sfQVjnNE

— The New York Times (@nytimes) August 1, 2024

When it was confirmed that Haniyeh was in his room at the guesthouse, the explosive was detonated remotely early on Wednesday, killing him and a bodyguard, officials said.

Photos showed that the explosion, which resulted in a loud noise, shook the building, shattered windows, and knocked down part of an exterior wall.

The report said a team of medics rushed to the room and declared Haniyeh dead. They tried, unsuccessfully, to revive the bodyguard.

Khalil al-Hayya, the deputy commander of Hamas in the Gaza Strip who was also in Tehran, arrived at the scene and saw Haniyeh’s corpse, officials said.

Sources told the newspaper the room next door, where Palestinian Islamic Jihad leader Ziyad al-Nakhalah was staying, was not badly damaged in the blast.

The report emphasized that it was not clear how the bomb made its way into the guesthouse. It also dismissed early speculation of a missile strike.

Iranian and U.S. officials have pinned the assassination on Israel, which has not publicly claimed responsibility for the attack, according to the report.

However, sources told the newspaper that Israeli intelligence officials briefed U.S. and other Western governments on the operation after it took place.

A top Israeli intelligence official had vowed to “take out” Hamas, including in foreign countries, after the group’s October 7 terrorist attacks.

In retaliation for the killing of Haniyeh this week, Iranian Supreme Leader Ayatollah Ali Khamenei ordered a direct strike on Israel.

Israel Defense Forces said on Thursday that a July 13 strike in Gaza killed Mohammed Deif, the commander of the terrorist group Hamas’ military wing, who was second only to Yahya Sinwar in the strip.

Israel Defense Forces confirmed on Thursday that the July 13 strike in Khan Younis killed Mohammed Deif, the commander of the terrorist group Hamas’ military wing, who was second only to Yahya Sinwar in the Gaza Strip.

“Deif initiated, planned, and executed the October 7th Massacre, in which 1,200 people were killed in southern Israel and 251 hostages abducted into the Gaza Strip,” Israel National News noted, adding, “Over the years, Deif directed, planned, and carried out numerous terrorist attacks against the State of Israel. Deif operated side-by-side with Yahya Sinwar, and during the war, he commanded Hamas’ terrorist activity in the Gaza Strip by issuing commands and instructions to senior members of Hamas’ Military Wing.”

The strike also killed Rafa’a Salameh, the Commander of Hamas’ Khan Yunis Brigade, as well as other members of the terrorist organization.

“[T]he air force had kept a series of five different pairs of aircraft and drones rotating through the role of hovering and passing by the residence where Deif was expected to visit Salame, such that the moment the war cabinet approved an operation, the air force would be able to open fire in practically no time at all,” The Jerusalem Post reported.

Although Deif had remained a shadowy figure for years, the morning of the October 7 attack, Hamas released a recording of him declaring the “Al Aqsa Flood” operation. “Kill, burn, destroy and block the roads. Make them understand that the Al Aqsa Flood is more powerful than they think and believe,” he said.

“Deif has been involved in Hamas’s operations for more than 20 years, plotting suicide bombings inside Israel, kidnapping soldiers, firing rockets and helping plan the tunnels used to launch attacks,” The Times of Israel reported in 2014, adding, “The Israelis see him as ‘the brains’ behind the campaign of suicide bombings that targeted buses and public places in Tel Aviv and Jerusalem until 2006.”