Muslims across the globe fasted Monday as the holy month of Ramadan began in Saudi Arabia, Qatar, the United Arab Emirates and other nations in the Middle East, Africa, Asia and elsewhere.

Observing Ramadan is the "fourth pillar" of Islam, and Muslims celebrate by forgoing food, drink, smoking and sex, among other activities. The fast runs from dawn to dusk and is broken each day with a meal known as "iftar." Muslims can also eat and drink during “suhoor” before dawn.

Breaking the fast involves different traditional foods, depending on the culture. In Egypt, Muslims often eat fava beans cooked with cumin and olive oil, while in Lebanon and Syria, flatbread served with thyme, cheese or yogurt is a popular treat.

The beginning of Ramadan is marked by the sighting of the crescent moon according to Islam's lunar calendar, but holy leaders often disagree on the start date. In Indonesia, the world's most populous Muslim country, fasting began Monday. Other countries in the Middle East and North Africa were expected to observe the holy month starting Monday or Tuesday.  

It is believed that the Quran was made known to the Prophet Mohammed during the holy month. The celebration ends with three-day holiday called Eid al-Fitr.

In Saudi Arabia, mosque leaders were expecting more than 100,000 visitors from across the Muslim world to visit the holy city of Mecca. 

“The presidency has made available all kinds of services and facilities for the worshippers, and these included appointing scholars to offer Islamic lectures and guidance classes, distribution of Islamic books and leaflets, organizing iftar meals, making available golf carts for carrying elderly and disabled worshippers, etc.," the government said in a statement. 

RTSG7D8 El Mesaharty Hussien, 40, wakes up residents for their predawn meals during the first day of Ramadan in Cairo, June 6, 2016. Photo: Reuters

In the United States, President Barack Obama recognized Muslim Americans celebrating the holy month amid growing hate crimes and attacks against Muslims across the nation. 

"I am reminded that we are one American family. I stand firmly with Muslim American communities in rejection of the voices that seek to divide us or limit our religious freedoms or civil rights," he said in a statement. 

Jibril Hough, spokesman for the Islamic Center of Charlotte, North Carolina, told Voice of America celebrating Ramadan in the United States instead of a Muslim-majority country is a unique experience that often inspires Muslims to gather at their local mosques and seek community instead of staying at home.

"The Ramadan experience is more collective," he said. "We are a religious minority in America and ...  especially toward the end of Ramadan, we bring food to the masjid [mosque]. It becomes more like a family reunion. A lot of times you see brothers and sisters that you haven't seen all year."

In the United Kingdom, London's new Muslim mayor, Sadiq Khan, said he would mark the beginning of the holy month by working to "build bridges" and break bread with Muslims and non-Muslims at synagogues, churches and mosques.

In China, minority Uighur Muslims have complained about bans against fasting under the ruling Communist Party, as well as rules that prohibit children from attending mosques, women wearing veils and young men growing beards.

Oman is among a handful of Muslim nations that declared Tuesday the first day of Ramadan. "The committee did not receive any notifications about Ramadan moon sighting, therefore Monday will be the 30th of Sha'aban and Tuesday 7th of June will be the first day of Ramadan," the Moon Sighting Committee in Oman said in a statement.

RTSG7QR People shop for the Muslim fasting month of Ramadan at the Shorja wholesale market in central Baghdad, June 6, 2016. Photo: Reuters

RTSG183 A decoration depicting dancing orphans is placed in front of al Amin mosque ahead of Ramadan in Beirut, June 4, 2016. Photo: Reuters RTSG2IE Palestinians test a cannon ahead of the Muslim fasting month of Ramadan in Rafah in the southern of Gaza Strip, June 5, 2016. Photo: Reuters

RTX2FJ3P A Turkish band plays music welcoming the holy fasting month of Ramadan in Tripoli, Lebanon, June 3, 2016. Photo: Reuters