A cannon was fired in eastern Saudi Arabia Saturday evening to signal the start of the holy month of Ramadan, when Muslims fast from dawn to dusk.

Several muffled cannon booms, traditionally fired after sunset each day of Ramadan, indicated fasting would begin Sunday, Information Ministry officials said.While Muslims observe a total fast, non-Muslims are banned from eating, drinking or smoking in public places during daylight hours.

Saudi Arabia on Wednesday threatened to deport non-Muslims who failed to observe the strictures of Ramadan. It did not mention the half-million mainly Western troops still in the kingdom.

"Those who do not abide by the law will have deterrent measures taken against them by the authorities concerned, including termination of their work and deportation from the kingdom," a statement said.

"Non-Muslim residents of this country should respect the feelings of Muslim and refrain from eating, drinking and smoking in the streets and in working and public places."

Muslims normally rise early to eat before sunrise during the month and stay up late at night for traditional Ramadan meals. Working hours are shortened. In Saudi Arabia government offices will be open only between 10 a.m. and 3 p.m.

The Saudi press agency said King Fahd sent cables of congratulations to about 30 Muslim leaders on the start of Ramadan.

They included Iranian President Akbar Hashemi Rafsanjani and Libyan leader Colonel Muammar Gaddafi.

There was no mention of Iraq and its sympathizers, among them King Hussein of Jordan, Palestine Liberation Organization leader Yasser Arafat and Yemeni President Ali Abdullah Saleh. Tunisian President Zine al-Abidine Ben Ali was also absent from the list.