Two people have died after a grenade attack near an open-air fruit and vegetable market in Rwanda's capital Kigali on Tuesday evening, police said on Wednesday.
Two people died among the 18 wounded, there are no suspects yet, a police spokesman said. He had earlier said 20 people were wounded.
There have been 11 blasts in the capital since early 2010 which have wounded around 100 people and killed seven.
The government has previously accused two former high-ranking army officers now in exile of being behind them.
One of the two men, Lieutenant-General Faustin Kayumba Nyamwasa, a former chief of staff and ambassador to India, denied involvement in 2010, saying the authorities had staged the attacks themselves.
Thirty other suspects are on trial over the blasts.
Diplomatic sources have said the attacks could have been carried out by more than one group.
(Reporting by Graham Holliday; Writing by James Macharia; Edited by Richard Meares)