Parliament on Tuesday renewed permission for a U.S.-led force to use a Turkish air base to patrol a no-fly zone over northern Iraq.

Allied planes take off from Incirlik air base in southern Turkey to monitor the zone established to protect Kurds. Parliament has extended the mandate for the patrols every six months since the end of the 1991 Gulf War when the zone was established.

Advocates of attacking Iraq next in the U.S. war on terrorism argue that Saddam is trying to rebuild a program for weapons of mass destruction that U.N. inspectors tried to dismantle after the 1991 Gulf War. Inspectors have not been allowed into Iraq since departing ahead of U.S. airstrikes in late 1998.

Iraq has since rejected the northern and southern no-fly zones and has routinely challenged allied aircraft since December 1998.