Saudi Arabia threatened on Tuesday to expel non-Muslim expatriates who eat, drink, or smoke in public during the Muslim fasting month of Ramadan.
Ramadan begins in the kingdom on Wednesday.
"Non-Muslim residents in the kingdom must not eat or drink in public during Ramadan, in respect to the holiness of Ramadan and the feelings of Muslims," said an interior ministry statement published by the official SPA news agency.
Foreigners caught breaking the fast in public "will be subject to deterrent measures that include terminating their employment contracts and expelling them from the kingdom," the ministry said.
It added that "companies, corporations and individuals are required to inform their employees" of the rules.
Oil-rich Saudi Arabia, which applies a strict version of sharia (Islamic) law, is home to eight million foreigners, mostly Asians.
During Ramadan, Muslims fast from dawn to dusk and strive to be more pious and charitable.
The month begins with the sighting of the new moon, which varies from country to country.
During Ramadan, Muslims are also required to abstain from drinking liquids, smoking and having sex from dawn until dusk. The fast is one of the five main religious obligations under Islam.
The month is sacred to Muslims because tradition says it is the month in which the Koran was revealed by Allah to the Prophet Mohammed.