KABUL - The spy service on Friday said a truck-borne bomb weighing eight tons -- the largest-ever seen in Afghanistan -- has been defused, thwarting a massive terror attack that could have destroyed an area around 1.5 kilometers (in radius).

National Directorate of Security (NDS) spokesman Shafiqullah Tahiri told reporters in Kabul that five suicide bombers riding the vehicle were killed and two others were captured alive following a clash in the 16th police district east of Kabul on Tuesday.

He alleged the plot had been architected by the Pakistan-based Haqqani network jointly with the Taliban leadership in Quetta, Balochistan province.

However, he could not offer any concrete evidence in support of his claim, but insisted it had been fortunately prevented by NDS officers.

Tahiri said the officers discovered the explosives during a night raid in the Alokhil area and that the explosives were hidden in cement bags. The target was a military facility in the capital, he said, but did not elaborate.

Journalists were shown the 7,800 kilograms explosives, including two rocket propelled grenades (RPG), two machineguns and some hand grenades which the NDS officials said they had seized from the truck.

The two detainees were also paraded before the media, but their identifies were kept secret. Tahiri said forged Afghanistan national identity cards had been recovered from the pair. (Pajhwok)