Kenyan security forces have pursued and killed more than 100 militants and destroyed their camp in Somalia after the ambush of a Nairobi-bound bus that left 28 people dead, Deputy President William Ruto said Sunday.

Somalia's Islamist al-Shabab militants have claimed responsibility for the attack Saturday, when gunmen ordered passengers on the bus to recite Quran verses and shot dead non-Muslims — 19 men and nine women — who could not.

The group said the killing outside Mandera, a town in the far northeast near the Somali and Ethiopian borders, was in retaliation for raids on mosques in the southern port city of Mombasa.