Six people have been arrested in South Africa over the shooting of a Rwandan dissident, police say.
Police spokesman Govindsamy Mariemuthoo refused to give the nationalities of the suspects but said more arrests were likely.
Former army chief of staff Lt Gen Faustin Kayumba Nyamwasa is recovering in hospital after what his wife called an assassination attempt.
Rwanda has denied any involvement in the shooting in Johannesburg.
The BBC's Karen Allen in Johannesburg says a Rwandan national known to Lt Gen Nyamwasa is believed to be among those detained.
Brig Mariemuthoo said the six would be charged with attempted murder but declined to give any more details, saying the investigations had reached a "sensitive stage".
Sources close to Lt Gen Nyamwasa told the BBC on Sunday that he was recovering and should be able to leave hospital in a few days.
Once a close confidante of Rwanda's President Paul Kagame, Lt Gen Nyamwasa fled to South Africa in February and has since accused the president of corruption - charges Mr Kagame denies.
Rwanda's government accuses Lt Gen Nyamwasa of links to grenade attacks in Kigali earlier this year and has previously tried to secure his extradition.
Lt Gen Nyamwasa has denied the allegations.
There have been several recent defections from the military ahead of elections due in August.
'Grabbed the gun'
The Nyamwasas had been returning from a shopping trip at around midday on Saturday (1000 GMT) when the gunman approached their car.
"[The gunman] spoke to my driver, but he wanted space to be able to shoot my husband," Rosette Nyamwasa told the BBC.
"Then when my husband bent, he shot. And fortunately, it went into the stomach and not in the head.
"My husband got out immediately.
"And he grabbed the gun. In that kind of scuffle, the guy couldn't cock the gun."
She added that Mr Kagame wanted her husband dead.
"[Mr Kagame] said it in parliament that he will actually kill my husband, that wherever he is he will follow him and kill him," she said.
But Rwanda's Foreign Minister Louise Mushikiwabo said in a statement that Mr Kagame's government "does not condone violence" and said she trusted South Africa to investigate the shooting thoroughly.
Lt Gen Nyamwasa also claimed the judiciary was compromised and told the BBC in a recent interview that the judges were now "President Paul Kagame's property".
A couple of months after Lt Gen Nyamwasa went into exile along with another top military officer, Mr Kagame reshuffled the military leadership.
At the time, two high-ranking officers were also suspended and put under house arrest.
Lt Gen Nyamwasa played an important role in the rebel Rwandan Patriotic Front (RPF), led by Mr Kagame, which put a stop to the killing and which is now in power.
But France and Spain have issued arrest warrants against Mr Nyamwasa for his alleged role in the lead-up to and during the genocide, along with other senior RPF figures.
Mr Kagame, in power for the past 16 years, is viewed by many in the West as one of Africa's more dynamic leaders.
However critics have raised concerns about his more authoritarian tendencies and the government has recently been accused of harassing the opposition ahead of the elections.