The "no-fly" zones over Iraq, which President Saddam Hussein has rejected for years, were imposed unilaterally by the western allies over the northern and southern part of Iraq at the end of the 1991 Gulf War after Iraq invaded Kuwait.
The air exclusion zones ban Iraq from using all aircraft, including helicopters. The zones have not been authorised by the UN Security Council but there have been few protests in the 15-member body, and most nations have turned a blind eye to them.
The Northern No-Fly Zone, covering 49,400 sq km, was set up by the US, Britain and France north of the 36th parallel in 1991 when Baghdad flew helicopter gunships to quell a Kurdish uprising. France pulled out of this watch more than a year ago.
A second, Southern No-Fly Zone zone was imposed by the three western allies south of the 32nd parallel in 1992 to protect Shia Muslims, who also rebelled against Baghdad.
Late in 1996, the southern zone was extended northward, closer to the southern suburbs of Baghdad, to the 33rd parallel, covering the southern third of Iraq. France declined to take part in the expansion.
In September 1996, President Saddam said he would no longer recognise the no-fly zones, calling them a breach of international law and the UN Charter.