The Israeli and American foreign intelligence services worked together to assassinate Hezbollah international operations chief Imad Mughniyeh in 2008, The Washington Post reports.

The U.S. never admitted its role in the killing. But former U.S. officials who spoke with the newspaper on condition of anonymity have now confirmed the CIA's involvement.

Mughniyeh was walking down the street in Damascus after having dinner on February 12, 2008 when a bomb planted in a parked SUV exploded, killing him. Prior to the blast, a team of CIA spotters were monitoring his movements in the Syrian capital as Mossad agents remotely triggered the bomb from Tel Aviv, according to the report.

Former U.S. officials told The Washington Post that the CIA and Mossad tracked Mughniyeh in Damascus for months prior to the assassination and worked closely to determine where the bomb should be placed.

The officials said that Israel was the first to approach the CIA about a joint operation to kill Mughniyeh. The U.S. wasn't concerned about blowback from Hezbollah because the organization was likely to blame Israel.

One ex-official told The Washington Post said the Bush administration had explained the killing as national self-defense, claiming Mughniyeh was actively plotting against the U.S. The Hezbollah leader had been implicated in the deaths of hundreds of Americans, including in the bombing that killed 63 people at the U.S. embassy in Beirut in 1983.

The U.S. explored ways to kill Mughniyeh for years, with greater urgency after the 9/11 attacks. Such a scenario was discussed in a secret meeting in Israel as early as in 2002, although it didn't materialize.

Only in 2006 did the Bush administration approve a series of operations against Hezbollah, which in 2003 began training militants in Iraq to attack U.S. forces and the forces of its allies.

“There was an open license to find, fix and finish Mughniyeh and anybody affiliated with him,” a former U.S. official who served in Baghdad was cited as saying.

U.S. intelligence officials had assured lawmakers that there would be no collateral damage. The bomb was tested repeatedly to ensure that no one else was hurt in the blast.

According to the report, the Israeli and American intelligence agencies tracked Mughniyeh's routine before deciding that his occasional solitary evening walks would present the best opportunity for the operation. It was the Mossad which raised the idea.