Indonesian Muslim women attend an evening prayer called 'tarawih', the night before the holy fasting month of Ramadan begins, at Istiqlal mosque in Jakarta, Indonesia, 31 Aug 2008

Muslims around the world are beginning to observe the holy month of Ramadan.

Most of the world's Muslims marked the first day of Ramadan on Monday, but the starting date varies in some countries depending on the sighting of the crescent moon.

Shi'ite Muslims in Iraq and Iran begin observing the holy month Tuesday, while Libya's Muslims started their observance on Sunday.

During the month, Muslims are expected to abstain from eating, drinking, smoking and sexual relations from dawn to sunset.

After nightfall, Muslims break the fast with a meal called "iftaar." Such meals have become harder to afford for low-income people because of rising global food prices.

Pakistan's government began the holy month by suspending a military offensive against militants in a northwestern tribal region.

Palestinian vendor sells dates in preparation for the Muslim holy month of Ramadan in the West Bank town of Jenin, 31 Aug 2008

Philippine officials said a crackdown on Muslim separatist rebels in the country's south will continue, but they promised "tactical adjustments" because of Ramadan.

Somalia's Islamist militia vowed to intensify attacks on government troops and their Ethiopian allies during the month, calling it a suitable time to wage a holy war.

Palestinians in the Gaza Strip began Ramadan Monday under the strain of a blockade imposed by Israel and Egypt since Hamas militants seized control of Gaza last year.

Egypt opened its border with Gaza on Saturday and Sunday in a humanitarian gesture ahead of the holy month, allowing hundreds of Palestinians to enter the country for medical treatment.

Ramadan is the ninth month of the Islamic calendar. It marks the time more than 1,400 years ago when Muslims believe the words of Islam's holy book, the Koran, were revealed to the Prophet Mohammed.

Ramadan will continue for the month of September, concluding with a celebration called Eid al-Fitr.

Some information for this report was provided by AFP and AP.