( CNN ) -- At least six people were killed and some 18 were wounded by an explosion in what appears to be a `` deliberate attack '' in Nairobi , Kenya , a senior Red Cross official tells CNN . Nine of the injured were listed in critical condition at Kenyatta National Hospital , the Kenya National Disaster Operation said on its Twitter account . The other wounded people were treated `` locally , '' the agency said . `` Our resolve & will to defend ourselves from those who intend to harm us will never be discouraged , '' the governor of Nairobi City County , Evans Kidero , said in a tweet . `` Our strength lies in our national unity . '' The explosion occurred in Eastleigh , a largely Somali neighborhood , east of the Nairobi city center . Authorities have not said what caused the blast . CNN 's Joseph Netto contributed to this report .
The explosion occurred in a largely Somali neighborhood . A senior Red Cross official said it appeared to be a ` ` deliberate . ''