Police spokesman Damas Gatare said today that a grenade exploded yesterday night at a busy market place in the Kigali suburb of Kicukiro, killing one person and wounded 14.
Another grenade was detonated today in the same area, killing one person and wounding eight, he said.
Three people have been arrested for their alleged roles in yesterday's attack, he added, giving no details about who was likely responsible for the blasts.
Since 2010 the country has been hit by grenade attacks that authorities sometimes blame on political dissidents.