East Africa vulnerable to Somali attacks across 'porous borders'

Ugandans are mourning the loss of more than 70 people who died in twin bombings in Kampala on Sunday.

The militant group al-Shabab claimed responsibility for the blasts, saying the attacks were to avenge the killings of Somali civilians by Ugandan soldiers who are part of an African Union force in Somalia.

This is the first time al-Shabab has struck outside of Somalia and there are fears they will strike elsewhere in the region.

BBC Network Africa's Audrey Brown spoke to former US Ambassador to Ethiopia David Shinn in Washington.

First broadcast on 13 July 2010