Saudi Arabia has warned pilgrims not to stage protests at the Hajj, a challenge to Iran which believes the event has political and spiritual dimensions.
A warning statement by the Saudi cabinet followed remarks by Iranian leaders about the pilgrimage, which takes place in the second half of November.
Supreme leader Ayatollah Ali Khamenei said Shiite Muslims should show they were addressing challenges to their unity. Khamenei also called on the Saudi authorities to take action against alleged mistreatment of Shiite Muslims in the country.
Iranian President Mahmoud Ahmadinejad said Tehran would take "appropriate measures" if Iranian pilgrims faced any restrictions during the pilgrimage.
Every year about two million Muslims, both Sunnis and Shiites, from around the world converge on Mecca to participate in the ceremonies.
4 November, 2009
Analysis and Forecast: increasing risk
There has been an increasing tension between the Sunni Saudi government and the Shiite Iranian regime. This has slowly been manifesting itself both covertly and overtly. Most recently, tensions between Sunnis and Shiites in both countries have sporadically erupted, as well as the deteriorating situation in Yemen, contributing to an increase of hostility between the two regimes.
The last major incident involving Shiite demonstrators in Saudi during the Hajj was in 1987 when several hundred anti-US demonstrators were killed. A recurrence of such an event is now more likely and threatens to spill into other areas of Saudi where there are large Shiite communities. This comes at a time of increasing internal tensions in Saudi, both in the Eastern province as well as in the south.
Sunni-Shiite clashes in the Hajj will likely carry longer term repercussions for Saudi and contribute to destabilizing the shaky situation in the Eastern province and in the south.
The figure below shows the approximate make-up of the Saudi population.