"The grenade attack happened at around 7 p.m. (5 p.m. GMT). Two young girls were slightly wounded... the police force immediately rushed them to the hospital", the spokesperson of the Rwandan police force, John Uwamungu, told Hirondelle on phone from Kigali.
According to the police, the attacker had arrived on a motorbike rode by another person. The attacker fled immediately after having thrown the grenade, added Uwamungu, stressing that the motorbike rider has been arrested for questioning.
"The investigation has started, we are questioning the driver of the motorbike", said the spokesperson.
It is the third time since last year the memorial, which holds the remains of 300,000 people killed during the genocide committed against mainly ethnic Tutsis in 1994, has come under attack.
At the time of the first attack, in April 2008, during the commemoration of the genocide, a police officer was killed.
According to the spokesperson of the police force, the authors of the two preceding attacks have still not been identified.
© Hirondelle News Agency