Muslims around the globe have begun preparations for Ramadan, a holy month of fasting and religious observance.

Men buy dates at a market in Unayzah, Saudi Arabia, a day before the start of the holy Muslim fasting month of Ramadan. (Hassan Ammar/Associated Press)

Official statements confirming Monday as the first day of Ramadan were issued late on Saturday in several countries, including Egypt and Saudi Arabia.

Its start is determined by the sighting of the crescent moon indicating the beginning of a new lunar month.

Some countries use astronomical calculations and observatories, while others still rely on the naked eye to determine the sighting, leading to sometimes different start and end dates of the holy month.

During the month, observant Muslims fast from sunrise to sunset, then often have large meals breaking the fast, with special foods and sweets.

Pakistan's top security official said the country will suspend its military operations against insurgents in a tribal region along the Afghan border in honour of the holy month.

The suspension is to take effect in the Bajur tribal area on Monday, said Interior Ministry chief Rehman Malik. He added, however, that security forces will retaliate with force against any militant attacks during the month.

With files from the Associated Press