Kenyan officials said gunmen, early Tuesday, killed more than 36 people working in a quarry in Mandera in northern Kenya.
The attack aimed at non-Muslims, was allegedly attributed to the Islamist terrorist group al-Shabaab.
One of the survivors said that all the Muslim workers were spared while Christians were shot or beheaded.
The police were quoted as saying that most of the victims were shot in the head, with some beheaded as the attackers struck around 1 am while the workers were sleeping.
The police said late Monday, three men with assault rifles attacked a club in the town of Wajir, killing one and injuring 13.
They said on November 22, 28 people were killed when al-Shabaab militants from Somalia hijacked a bus in Mandera, and shot dead passengers who failed to read verses of the Koran.
They also said that the Kenyan security forces pursued the militants over the border with Somalia, killing more than 100 of them.
Many of the 60 bus passengers were Kenyan government officials, police officers, health workers and teachers.