A phone call as the dusitD2 complex terror attack unfolded helped security forces to crack a terrorist network behind the raid in which 21 people were killed.

A man who saw the registration number of a car whose image was broadcast last Tuesday as the one that ferried the terrorists to the scene of the attack at 14 Riverside Drive called police and told them he had seen the car leave Guango estate in Kiambu County on several occasions.

The Standard is aware of the man - and police have corroborated this account - but we cannot reveal it for his own safety.

Administration policemen on the ground were alerted and went to the estate. They barricaded it at about 8pm on Tuesday, hours after the gunmen had stormed the complex and started to kill people.