A total of 12,975 people were arrested for violations of residency laws, while 4,185 were held over illegal border crossing attempts, and a further 3,722 for labor-related issues.
The Ministry of Interior said that anyone found to be facilitating illegal entry to the Kingdom, including providing transportation and shelter, could face imprisonment for a maximum of 15 years, a fine of up to SR1 million ($267,000), as well as confiscation of vehicles and property.
Suspected violations can be reported on the toll-free number 911 in the Makkah and Riyadh regions, and 999 or 996 in other regions of the Kingdom.
Saudi security forces detained 20,882 people last week in a sweeping campaign targeting illegal residents, the Interior Ministry announced.
The arrests came during joint inspections with government agencies conducted between August 28 and September 3.
Among those detained were 12,975 violators of residency laws, 4,185 who breached border security regulations, and 3,722 who violated labour laws. Authorities deported 10,895 people, while thousands more were referred to their embassies or placed in custody to finalise travel arrangements.
Officials said 1,244 people were caught attempting to cross into the kingdom illegally, most of them from Yemen and Ethiopia. Another 20 individuals accused of transporting or sheltering violators were also detained.
The ministry warned that facilitating illegal entry or providing assistance to violators could bring up to 15 years in prison, fines of SR1 million, and confiscation of vehicles or property. Citizens were urged to report violations via emergency hotlines.