Updated

A Kenyan official says suspected al-Shabab extremists have killed three teachers in an overnight attack in the northeastern county of Wajir.

North Eastern regional coordinator Mohamud Saleh says an unknown number of gunmen attacked Qarsa primary school and targeted non-Muslim teachers. Saleh says a rescue team responding to the attack ran over an improvised device but no one was injured.

Education along Kenya's border with Somalia has been greatly hindered after non-Muslim teachers refused to work in the region following the extremist group's targeting of non-Muslims starting in 2014 that left dozens dead.

Al-Shabab has vowed retribution after Kenya sent troops to Somalia in 2011 to fight the extremists in the Horn of Africa nation.