Two people have been killed in clashes in Saudi Arabia amid a nationwide crackdown on illegal expatriates.

Two people have been killed in clashes in Saudi Arabia amid a nationwide crackdown on illegal expatriates, KSA police said on Sunday.

They said they intervened on Saturday after foreigners rioted in the poor Manfuhah neighborhood of Riyadh, attacking Saudi and other foreign residents with rocks and knives.

One Saudi and another person, whose nationality and identity remains unknown, were killed, said a police statement carried by the SPA state news agency.

Another 68 people -- 28 Saudis and 40 foreigners -- were injured and 561 people were arrested.

The Manfuhah district of the capital is home to many illegal migrants, mostly from east Africa.

Saudi police claimed on Saturday illegal migrants in Manfuhah have been given the chance to come forward and that accommodation has been made available while their repatriation is arranged.

On Monday, the authorities began rounding up thousands of illegal foreign workers following the expiry of a final amnesty for them to formalize their status.

Expatriates account for a full nine million of the oil-rich kingdom's population of 27 million.