At least one person is killed and nine wounded after a suicide bomber detonates a grenade near a military base in Nairobi Friday.<br/> <br />The blast occurred in a Somali-dominated area.<br/> <br />Nairobi has blamed Somalia's al Qaeda-linked al Shabaab, which has threatened to retaliate after Kenya pursued the Islamists in Somalia in October.<br/> <br />One eyewitness says the police were powerless:<br/> <br />(SOUNDBITE)(English) UNNAMED EYEWITNESS, SAYING:<br/> <br />"So to make it worse, our police officers did nothing to stop the car from speeding past them."<br/> <br />The attack comes just hours ahead of a visit to Kenya by U.S. Secretary of State Hillary Clinton. Clinton's trip is expected to partly focus on U.S. security ties in the face of growing threats from Islamist militants.<br/> <br />Deborah Lutterbeck, Reuters.