Angry scenes have been reported at Cairo airport as security forces barred Muslim pilgrims from travelling to Mecca because of fears over swine flu.
Hundreds staged a sit-in on Sunday when the Egyptian authorities implemented a plan to prevent anyone over 65 and under 25 from travelling to Mecca.
Another 180-200 belonging to the banned age groups were held back on Monday.
The curbs could affect large numbers of old people, some of whom expend great efforts to visit Mecca before dying.
An airport official said about 15% of would-be passengers to the Muslim holy city had been turned back on Monday.
"The people banned from leaving are those over 65 and those under 25 because they are the most at risk of being contaminated by swine flu," the official added.
This year, the main annual pilgrimage, or Hajj, to Mecca takes place in November, but the city hosts many Muslims during the rest of the year on the lesser pilgrimage, or Umrah.
The most holy month of Ramadan, which begins this weekend, is an especially popular time to perform the lesser ritual.
However, Arab health ministers have agreed to restrict Hajj and Umrah numbers this year because of the risks of infection by the H1N1 pandemic.
In July, an Egyptian woman returning from the Umrah became the first person to die of swine flu in the Middle East and Africa.
Performing the Hajj is incumbent upon all Muslims who have the means to make the journey to Mecca.
Egyptian officials said anybody prevented from boarding flights to Mecca would be reimbursed.
Iran banned all pilgrimages to Saudi Arabia during Ramadan in an attempt to contain the spread of the virus.