Death waited for Hamas chief Ismail Haniyeh for over two months. A bomb was secretly smuggled into the guesthouse in Iran where he was expected to arrive, reports The New York Times citing several officials in the US, Iran, and other Middle Eastern regions.

It was hidden in the guesthouse in a posh locality in Tehran, protected by the Islamic Revolutionary Guards Corps (IRGC) – around two months ago. The guesthouse was inside a large compound used by the IRGC for their secret meetings and housing important guests.

The wait, though, was long, it was fruitful.

Haniyeh, a top Hamas negotiator who had led its political delegation in Qatar, arrived in Tehran to attend the swearing-in ceremony of Iran’s president Masoud Pezeshkian.

On Tuesday morning, it was confirmed that he was in his room in the guesthouse and the assassins detonated the bomb remotely, reported NYT. The blast shook the building. A portion of the wall collapsed. Windows were shattered.

Haniyeh and a bodyguard were killed in the attack that Hamas called a “treacherous Zionist raid on his residence in Tehran”. The Palestinian group engaged in a deadly fight over Israel’s Gaza campaign called it a “grave escalation” as it accused Israel for the assassination.

The Hamas chief’s killing threatened to disrupt talks to end the war and unleash another wave of violence.

Israel hasn’t claimed responsibility yet. But the report states that Israeli intelligence officials had shared details about the covert operation with western officials in the immediate period.

Top US diplomat Antony Blinken had denied that the US had prior knowledge about the assassination plot.

It was speculated earlier that Haniyeh was killed in a missile strike, but the missile theory raised doubts over how Israel evaded the air defence systems in the Iranian capital. The damage caused was minimal, much lesser than what a missile strike would have done.

The report found the assassins were able to find a gap in the Iranian security to smuggle in the bomb, though it remains unclear how they managed to keep it hidden for two months.

There were rumours of witnesses seeing a missile-like object hitting the window of Haniyeh’s room, but Iranian officials have confirmed that the blast occurred inside the room and that the bomb had been placed in advance.

According to Middle Eastern officials, it took months for the planning and needed detailed surveillance of the compound. The planning was so precise that the next room, where Palestinian Islamic Jihad leader Ziyad al-Nakhalah was staying, wasn’t as badly damaged.

The assassination has caused tremendous embarrassment for Iranian officials who are yet to find out how or when the bombs were planted.

A medical team housed in the compound declared Haniyeh dead. They failed to revive the bodyguard too.

Israel’s spy and foreign intelligence agency Mossad is primarily tasked with assassinations outside the country. Mossad chief David Barnea had vowed to hunt down Hamas leaders after the October 7 attacks.

He had said it would take time, like it had after the Munich massacre, to get hold of the Palestinian leaders.

Barnea was referring to the murder of 11 Israeli athletes by Palestinian operatives at the 1972 Olympics in Munich. Mossad had activated its hit squad to carry out the ‘Operation Wrath of God’ covert operation, codenamed Bayonet, to avenge the murders.