In 1979 five children from the Netherlands were eating oranges when they started to complain about the bitter taste.
It turned out the oranges had been spiked with the poisonous heavy metal mercury. Luckily the children were taken to hospital where they had their stomachs pumped and were released a few days later apparently none the worse for their ordeal.
According to an article in the newspaper Observer Reporter (which is now available on google news), a letter addressed to 18 countries was received by a western news agency in London claiming that the poisoning was “designed to sabotage the Israeli economy” and was carried out by the Arab Revolutionary Army Palestinian Commando.
Contaminated oranges were also found in Darmstadt in Germany.