The explosives were found in a truck from neighbouring Pakistan which had entered the eastern province of Nangarhar, spy agency spokesman Lutfullah Mashal told a press conference AFP reported.
The attack was planned for Afghan new year celebrations on Tuesday in either Kabul or Nangarhar, he said. The find was made in early March.
"Nine tonnes of explosives were hidden under a banana consignment in a lorry. The owner of the truck has fled back to Pakistan, but his Afghan driver was arrested by the Afghan security forces," Mashal said.
Celebrations marking the beginning of spring and the Afghan new year, known as Nawruz, were banned under Taliban rule.
Source : Afghan voice Agency (AVA), Kabul