Gunmen blasted their way into a hotel and office complex in the Kenyan capital on Tuesday, killing at least seven people and sending workers diving under desks from an attack claimed by Somali Islamists al Shabaab.
Police warned the "terror attack", which echoed a 2013 assault on a Nairobi shopping center, may be ongoing, with assailants still inside the upscale 14 Riverside Drive complex.
Nairobi is a major expatriate hub, and the compound attacked houses offices of various international companies.
"The main door of the hotel was blown open and there was a human arm in the street severed from the shoulder," said Serge Medic, the Swiss owner of a security company who ran to the scene to help when he heard of the attack from his taxi driver.
For more details, watch the full report in the video above