The injured, mostly children attending a Sunday school service were rushed to Guru Nanak hospital. However, one child has already been discharged while seven children are still admitted.
“So far, we can confirm that one child has succumbed to injuries,” Nairobi police boss Mr Moses Ombati told Nation.
“Other victims were injured in a stampede after the incident,” he added.
According to a church goer, Mr Jackson Mwangi, the attacker threw a grenade at around 10.30am on the Sunday school section.
Police at the scene cordoned off the area to stop any secondary attacks.
Bomb experts, fire brigade and ambulances arrived at the scene shortly thereafter. However, most people interviewed at the scene said they did not see any attacker but only heard the blast.
Three people arrested at the scene taking photos of the church told police that they were working for the Hon Cable TV of Somalia.
Tension gripped the area as enraged youth started attacking the nearby Alamin mosque. However, police managed to restore calm and dispersed them.