Armed robbers on Friday morning attacked Sakina Church in Nairobi's Makongeni area.
The robbers are reported to have killed two worshippers who were in the church.
Reports by The Star indicated that the attackers stabbed one of the victims severally, killing them on the spot.
According to Makadara DCIO Henry Kiambati, the robbers made away with several musical instruments that belonged to the church.
He added that they were yet to assess what had been stolen from the premises and establish the motive of the robbery.
In a past incident, a terror suspect was arrested for spying on a Catholic church in Baragoi just before a Sunday morning mass.
The 22-year-old was in the company of an accomplice who managed to escape a police dragnet.
Police believed the suspects were on a surveillance mission in the area for a probable terror attack.
Police commander Karanja Muiruri reported that the suspects had begun surveying the church early in the morning and when worshippers started arriving, they started collecting information from unsuspecting church-goers about the number of congregants who attend mass, the church capacity and where the bishop and priests reside.
Worshippers soon grew suspicious about the men's intentions when they realised they were not interested in the church service.
