Several people have been wounded in a grenade attack in the Rwandan capital, witnesses and officials say.
The blast in Kigali came just two days after President Paul Kagame was re-elected in a landslide win.
The explosion injured seven people, including two children, AFP news agency quoted a police spokesman as saying.
The spokesman, Eric Kayiranga, said the attack happened at rush-hour on Wednesday evening, near the city's main bus station.
It was not immediately clear who had carried out the attack.
The Associated Press cited a witness saying some people were lying on the ground at the site of the blast and others were running around screaming.
There were blood stains on the ground and a motorbike lying on the street, the report said.
"I saw a grenade [rolling] past and then I felt myself falling down," said witness Michael Mugisha, who was being treated in hospital.
"People were running. There were so many people."
There were several grenade attacks in Kigali earlier this year amid rising political tension ahead of this week's presidential election. No-one claimed responsibility for the attacks.
There was an attack in May, and another in March, when the city was rocked by two simultaneous blasts which injured several people.
Mr Kagame has led Rwanda since hundreds of thousands of people were killed in the 1994 genocide. He won 93% of the votes in Monday's poll, the electoral commission said.
Observers from the Commonwealth, which Rwanda joined last year, said the campaign was marked by "a lack of critical opposition voices".
Mr Kagame's critics accuse him of suppressing opposition and undermining democracy.