Angolan authorities have expelled 2,884 Congolese illegal migrants, state-owned media confirmed.
State news agency Angop said the illegal migrants were rounded up in Lunda Norte Province between September and October.
Lunda Norte Province is located 656km north of the capital Luanda, and shares borders with both DRC and Congo-Brazzaville.
"During the police operation, 10,128 other DRC nationals voluntarily left the diamond exploration areas," Angop quoted Lunda Norte police boss Rodrigues Zeca saying.
"The police also confiscated from the migrants 80 dredges and 78 pieces of diamond," Mr Zeca was further quoted.
Illegal migrants were often attracted to Angola for diamond exploration and business opportunities.
Angola has extensive diamond reserves, principally in the Lunda Norte and Lunda Sul provinces in the northeast.
The two provinces border both the DR Congo and Congo-Brazzaville.
The conflict in DR Congo has forced thousands of nationals to flee to Angola and other neighbouring countries.
A fortnight ago, Angolan authorities expelled 432 illegal foreign nationals from Cabinda Province.
The majority of the deportees were from the DR Congo, with a few others from the Republic of Congo.