Most of the world's 1.2 billion Muslims began Ramadan on Thursday, a holy month of dawn-to-dusk fasting, festivities -- and abstinence.

The start of Ramadan, the ninth and holiest month of the Muslim calendar, is traditionally determined by the sighting of a new crescent moon.

Across much of the Muslim world, Ramadan begins on Thursday, although Libya kicked off the festivities on Wednesday, the same day as Nigerian Muslims.

During the holy month, Muslims are required to abstain from food, drink and sex from dawn until dusk as life slips into a lower gear during the day, and activity peaks between "iftar," the breaking of the fast at sunset, and "suhur," the last meal of the day before sunrise.

In Indonesia, the world's most populated Muslim nation, Ramadan began under the shadow of the latest earthquake disaster after a massive 8.4 tremor struck off Sumatra island.

At least two people were confirmed dead as emergency teams headed for the remote region.

In multicultural Singapore, Ramadan is just one of the holidays being celebrated, along with the Chinese mid-autumn festival and the Indian Deepavali festival next month.

In Bangladesh, the government has offered rice at a 20 percent discount around the country, while also opening 100 convenience stores around the capital Dhaka to sell other foods at reduced prices.

In Cairo, a shopping frenzy began weeks ago despite soaring prices, as the faithful prepare for the first day of Ramadan where extended families break the fast with dates and milk.

In the teeming city of 18 million notorious for gridlock, traffic police have been banned from taking time off during Ramadan, with extra wardens deployed to control pre-iftar accidents as cars clamour to get home in time for iftar.

Gaza residents spending their first Ramadan under Hamas, which seized control of the tiny territory in June, are bracing for clashes after Fatah and other Palestinian groups called for sunset street prayers despite a Hamas ban.

But the weary inhabitants were just hoping for a few weeks of peace and calm with their families during Ramadan after months of deadly partisan violence.

In a traditional gesture, the Islamist movement Hamas announced on Wednesday the release of 84 prisoners in the Gaza Strip.

Saudi Arabia is preparing to receive around one million pilgrims expected to perform "umrah," or a smaller pilgrimage, to Mekkah.

PHOTO CAPTION

Afghan boys read the Quran at the Hazrat-e-Bilal madrassa (religious school), in Kabul, ahead of the start of the holy month of Ramadan. (AFP)

AFP