The 1994 Heathrow mortar attacks were a series of homemade mortar bomb attacks targeted at Heathrow Airport carried out by the Provisional IRA. Over a five-day period, Heathrow was targeted three times (9, 11, and 13 March) by the IRA, which fired 12 mortars rounds. Heathrow was a symbolic target due to its importance to the United Kingdom's economy, and much disruption was caused when areas of the airport were closed over the period due to the IRA attacks. The gravity of the incident was heightened by the fact that Queen Elizabeth II was being flown back to Heathrow by the RAF on 10 March.