Al-Shabab gunmen killed 14 people, mostly quarry workers, officials said, in an overnight attack on a residential complex in northeast Kenya that the Islamic militant group said had targeted Christians.

Many died in their sleep, the Kenya Red Cross said. The raid, in the town of Mandera, mirrored one in the same county in December in which 36 quarry workers died.

Al-Shabab has made a series of deadly incursions into Kenya, saying it will continue until Nairobi withdraws troops from an African Union force fighting the militants in Somalia.