Egypt is tightening rules for visas by requiring individual visitors to obtain them at embassies instead of on arrival at Egyptian airports, the Foreign Ministry said on Tuesday, a move that may make it harder to revive the tourism industry.

Security sources, however, said the decision arose from a need to give intelligence services more time to assess individuals who want to visit Egypt, where security has suffered from an Islamist insurgency centred in the Sinai region.

"The system remains unchanged for tourist groups which can obtain visas at airports, but individuals have to get a prior visa from embassies," Foreign Ministry spokesman Badr Abdelatty said.

The changes will take effect on May 15, said Rasha Azaizi, the tourism minister's media adviser. "The decision will have a small effect... The industry depends on the large groups brought in by tour operators," she told Reuters.

Egypt's economy has been hammered by a precipitous fall in tourist visitors and a lack of foreign investment because of protracted political upheaval since the 2011 popular uprising that toppled autocrat Hosni Mubarak.

Reviving the tourist sector is central to efforts to shore up state coffers in a country which once attracted huge numbers of visitors to ancient sites like the pyramids, Luxor and Aswan along the Nile, and Red Sea resorts.

Security sources said another reason for the change in visa rules was to put stronger controls on visits by Western human rights activists who have been highly critical of Egypt's tough crackdown on Islamists and liberal activists.

Egypt hopes to generate $20 billion in revenue from tourism by 2020 by attracting 20 million visitors, new Tourism Minister Khaled Ramy told Reuters on Sunday at an international investment conference in the Red Sea resort of Sharm El-Sheikh.

More than 14.7 million tourists visited Egypt in 2010. That dropped to 9.8 million in 2011, rose the following year to 11.5 million but shrank back to about 10 million last year. - Reuters