Kenyan and Ugandan officials have linked the blast to Al Shabab, the Somali militia that took credit for a July suicide bombing that killed 79 at two restaurants in Kampala, Uganda.
Several Pakistanis are among those detained in connection with Al Shabab's Uganda bombings during the World Cup final on July 11. The Al Qaeda-linked Somali group claimed responsibility for its first terrorist attack outside Somalia.
Less than 48 hours after twin Uganda bombings claimed by Somalia's Al Shabab militants killed 76 people, the Somali community in Uganda is now worried about being attacked. An unexploded suicide vest was found Monday and four foreigners arrested.