Four top Rwandan army officers have been suspended and placed under house arrest, suspected of doing business deals in neighbouring Democratic Republic of Congo, the army said.

The four, who include two intelligence chiefs, "are under investigation for acts of indiscipline with respect to getting involved with civilians in business dealings in the DRC," army spokesman Colonel Joseph Nzabamwita said in the statement issued late Wednesday.

They "have been suspended from their posts and placed under house arrest," he said.

He named them as Lieutenant General Fred Ibingira, head of the reserve forces; military intelligence chief Brigadier General Richard Rutatina; Brigadier General Wilson Gumisiriza, a division commander; and Colonel Dan Munyuza, head of external intelligence.

Rwanda is accused on a regular basis, notably by the United Nations, of illegally exporting minerals mined on the other side of the border.