Amin said that the fact that he was killed in Damascus was a major security breach for the Syrian government and that his presence in Syria was significant since he had been underground for years.
There have been many attempts on Moghaniyah's life in the past 20 years, she reported.
His death comes amid a continuing political power vacuum in Lebanon, with opposing political factions failing to agree on a new president and the distribution of key cabinet portfolios.
Moghaniyah's funeral is set to coincide with the anniversary of the death of Rafiq al-Hariri, a former Lebanese prime minister who was killed in a bomb blast in Beirut in 2005.
Al-Hariri's son, Saad al-Hariri, currently leads the ruling March 14 coalition bloc in Lebanon, which has faced growing opposition by Hezbollah and its political allies.
An Israeli cabinet minister hailed the killing, but said he did not know who was behind the attack.
Gideon Ezra, the Israeli environment minister, said: "I, of course, do not know who carried out the assassination of Imad, but he should be blessed."
The comment was the first by a member of the Israeli government of Ehud Olmert, the prime minister.
Later on Wednesday, Olmert's office denied allegations that it played any role in the killing.
|Moghaniyah died in a bomb blast in|
Damascus, the Syrian capital [AFP]
"Israel rejects the attempts of terror elements to attribute to Israel any involvement in this incident," his office said in a statement.
Israeli news media predicted that Hezbollah would attempt to carry out revenge attacks against Israeli targets.
Israeli radio and television interrupted their normal programming to announce the death of what one broadcaster called "the most dangerous of terrorists in the Middle East in the past 30 years".
"The score has been settled: Imad Moghaniyah was liquidated in Damascus," read the headline on YNetNews, the website of Israel's biggest-circulation daily, Yediot Aharonot.
Privately run Channel Two television immediately called for security to be increased at Israeli diplomatic missions around the world.
The Palestinian Hamas movement joined Hezbollah in accusing Israel of the assassination, saying it was a "new example of Zionist gangsterism".
The movement called for the Arab world to unite against Israel.
Sami Abu Zuhri, a Hamas official, said: "We urge the Muslim and Arab nations to act decisively against the Zionist [Israeli] octopus that threatens the security of Arab and Muslim countries."
Abu Zuhri warned Israel of "unprecedented responses" if it carried out any assassinations in Gaza.
According to the US and the West, he was a "top terrorist" and was involved in the bombing of the US embassy in Beirut in April 1983.
The US also claims he was involved in the killing of hundreds of US marines and French paratroopers in simultaneous truck bomb attacks in October 1983.
|Hezbollah officials and relatives of Moghaniyah|
mourned his death in Beirut [AFP]
The blast late on Tuesday took place in the upmarket Kafar Soussa residential neighbourhood of Damascus.
Al Jazeera's Abdul Hamid Tawfiq, reporting from Damascus, said the blast targeted a silver-coloured vehicle in a car park.
Syrian security forces cordoned off the site and prevented any one from taking pictures, even by mobile phones, he said.
"When taking a close look at the car, we noticed that it was not burnt or blackened, but the driver's and passengers' seats were damaged," Tawfiq said, stressing that he believed that a bomb was planted under the driver's seat.
There have been a number of attacks in Damascus in recent years, including one on the US embassy in 2006 that left three gunmen and a Syrian guard dead.
Hezbollah is backed by both Syria and Iran.