Baku, January 6 AZERTAC Tajik President Emomali Rahmon, his spouse and their children performed a pilgrimage, known as the Umrah, on January 4 as part of their visit to Saudi Arabia. The Tajik leader's website has reported that it was the second time Rahmon had had the honor to enter the Kaaba and pray there. The Tajik leader prayed at the Kaaba for the first time in December 2005, when he attended a meeting of Organization of Islamic Cooperation leaders. The Kaaba is a square building surrounded by the Masjid al-Haram, which is the world's largest mosque, located in the center of Mecca. Until recently, all worshippers were allowed to enter the Kaaba and pray there twice a week. But this has now become impossible due to a rapidly growing number of pilgrims and other factors. Today the Kaaba is opened only twice a year and only for special guests. The Umrah is a pilgrimage performed by Muslims to Mecca, Saudi Arabia, that can be undertaken at any time of the year, in contrast to the hajj, which must be performed during a specific period of time in the Islamic calendar.