South African police arrested 19 suspected Democratic Republic of Congo (DRC) rebels in the north of the country in a dawn raid on Tuesday, police said.
The early morning arrests followed months of intelligence gathering about the alleged rebels "whose objective is believed to be to overthrow the current government of the Democratic Republic of Congo," police said in a statement.
The men are due to appear in a Pretoria court later this week on charges of "transgressing the Foreign Military Assistance Act", they added.
National police spokesman Lindela Masigo said the alleged rebels were nabbed on the outskirts of the country's northern Limpopo province.
DR Congo has been trying to contain a rebellion by the Movement of March 23 (M23), which has been fighting the army since May last year in the country's volatile Kivu region in the unstable east.
The DR Congo government spokesman, Lambert Mende, said Kinshasa had been informed of the "arrest of 19 plotters" and added that "they were arrested just as they wanted to take action".
"Contacts have been established to see what would be the best step: either they are tried in South Africa, or they are deferred before a Congolese court. The ministry of justice is working on it and will recommend to us the best procedure," Mende told AFP.
He added that "at this stage", his government could not say whether the suspected rebels belonged to M23.
South Africa counts around 300,000 DR Congo immigrants.