Gigiri OCPD Vitalis Otieno confirms that one of the GSU officers was stabbed and wounded on the head and hand before he shot the assailant dead. PHOTO: COURTESY

A man was shot dead outside the US embassy in Gigiri after he tried to stab a GSU officer manning one of the gates.

PoliceThursday said the man, claimed to be in his early 20s, had run directly at the officer with a knife in hand and without engaging the policeman, went for his head.

But the policeman acted swiftly and blocked the weapon that was aimed at his head, in the process sustaining injuries. Both the police and the embassy confirmed the incident.

"The US embassy confirms there was a shooting incident near the embassy. No embassy personnel were involved. We refer you to Kenyan authorities for further details," the embassy stated in a brief communication sent to the mediaThursday evening.

Gigiri police boss Vitalis Otieno said the police officer sustained stab wounds on the head and one hand before he shot the assailant dead in defence.

"The assailant came running to the entrance where the officer was and attacked him, stabbing him in the hand and the head. The officer had no other option but to react by shooting him three times in defence. We are yet to establish the motive of the attack," said Mr Otieno.

The incident that occurred Thursday afternoon led to increased security around the area, with officers from the Federal Bureau of Investigations (FBI) called in to help in the investigations.