Kenya bus attack: Al-Shabab claims responsibility

Gunmen from the Somali militant group al-Shabab have claimed responsibility for the deaths of 28 people in an attack on a bus in northern Kenya.

The bus was travelling to the capital, Nairobi, when it was stopped in Mandera county, not far from the Somali border.

The militants claim the attack was in response to recent Kenyan government arrests and raids on mosques in Mombasa.

Security correspondent Frank Gardner reports.