The 2006 transatlantic aircraft plot was a terrorist plot to detonate liquid explosives, carried on board airliners travelling from the United Kingdom to the United States and Canada, disguised as soft drinks. The plot was discovered by British police during an extensive surveillance operation. As a result of the plot, unprecedented security measures were initially put in place at airports. The measures were gradually relaxed in the following weeks, but passengers are still not allowed to carry liquid containers larger than 100 ml onto commercial aircraft in the UK and most other countries, as of 2021.