The attackers of DusitD2 Hotel on Tueday had planned a twin assault in Mombasa, police say.
The attack in Nairobi happened in Dusit Complex on 14 Riverside Drive, but the Mombasa targets have not been revealed.
Police foiled the attack after communication from the DusitD2 planners leaked.
The terrorists had started ferrying weapons and explosives from Malindi after sneaking in through Boni Forest.
But reports indicate they cancelled the plans after police mounted roadblocks in search of a 14-seater matatu that was to deliver the ammunition.
A senior police officer told the Star the attackers had already left Boni and were holed up in Majengo.
The details emerged yesterday after the father and widow of DusitD2 suicide bomber Mahir Khalid Riziki were set free after lengthy questioning.
The father, who is yet to be identified, and widow Suhaila Mwalim Bakari were arrested at Majengo and Bakarani areas respectively.
Bakari declined an interview with the Star, saying she felt unwell.