Egypt's justice minister sent back a letter Tuesday from the U.S. ambassador asking him to lift the travel ban on Americans working with pro-democracy groups in the country.

Justice Minister Adel Abdel-Hamid said the letter should have gone to the judges investigating the groups, not to him. He also said the letter should not have come from the ambassador but instead from those affected by the travel ban.

Egyptian parliamentary speaker Mohamed Saad al-Katatni called the letter unacceptable interference from the U.S. ambassador.

in Washington, U.S. State Department spokesman Mark Toner said the travel restrictions are unfair and onerous and should be lifted immediately.

Egypt has barred a number of foreigners, including six Americans, from leaving the country. They include Sam LaHood — son of U.S. Transportation Secretary Ray LaHood.

Egyptian authorities say they cannot leave while officials investigate alleged criminal activities by non-governmental organizations working to support Egyptian elections.

The State Department says the NGOs are totally non-partisan and do not support or give money to any individual candidates.