SAMARRA, Iraq: Reconstruction of holy shrine of Al-Imamayn Al-Askariyain (peace of Allah be upon them) in Samarra has begun on Tuesday February 5 two years after it was badly damaged in a terror bombing while Iraq's National Security Adviser Mowaffak al-Rubaie warned that the building project could take many years to complete.

Around 60 workers began digging through the rubble under the golden dome of the thousand-old Al-Askari shrine in Samarra, 125 kilometers (80 miles) north of Baghdad that was destroyed by Al-Qaeda bombers.

The two distinctive minarets of the sacred shrine were leveled in a second bombing in June last year.

In a statement in Baghdad, Iraqi premier Nuri al-Maliki said the rebuilding of the holy shrine was a "blow to all those who want to stoke sectarian violence and drive Iraq towards civil war".

The United Nations Educational Scientific and Cultural Organisation (UNESCO) has helped in the reconstruction efforts.

Mohamed Djelid, director of UNESCO's Iraq office, said the Iraqi government was financing the project and was "determined to transform Samarra into a city that deserves to be registered as a UNESCO World Heritage site."

The mosque houses the remains of the 10th and 11th imams -- Ali al-Hadi and Hassan al-Askari -- buried in the house where they died in the ninth century and around which the shrine was built.

The massive golden dome, about 20 metres (66 feet) high and with a diameter of 68 metres (223 feet), was added in 1905. It was covered in 72,000 gold pieces and surrounded by walls of light blue tiles.

The mosque has been closed since the attack on February 22, 2006, and the city's skyline is still disfigured.

A government official, requesting anonymity because of the sensitive nature of the project, told AFP that restoration work had been delayed because "there are a lot of threats against people working on this project."