The Somali extremist group Shabab attacked a quarry in northern Kenya on Tuesday, killing dozens of workers 10 days after a bus attack the group claimed responsibility for in which gunmen shot and killed 28 passengers who couldn't recite a Koranic verse.
After the quarry assault, Kenyan Police Chief David Kimaiyo submitted his resignation, which was accepted by President Uhuru Kenyatta, according to media reports. Kenyatta dismissed Interior Minister Joseph Ole Lenku and nominated as his replacement opposition politician and retired army Gen. Joseph Nkaissery.
In recent weeks, Islamist extremist groups on opposite sides of the continent -- in Kenya and Nigeria -- have carried out attacks killing hundreds, with security forces in both countries accused of lapses for their failure to contain the violence.
Officials said the quarry workers attacked Tuesday morning were ambushed in Koromei, local media reported. The workers were sleeping in tents when the attack began, and Kenya's Red Cross and local officials reported that 36 were killed.
Thirty-two of the dead were shot in the head by the assailants -- like the bus attack victims -- but four were beheaded, Reuters reported, citing a witness.
Photos of the quarry victims posted online Tuesday bore a chilling resemblance to the scene of the bus shooting, with victims lying on the ground in a long line.
The Shabab, an Al Qaeda-linked group, claimed responsibility for Tuesday's attack in addition to last month's bus massacre. Both attacks were near the northern town of Mandera, near the Somali border, and both saw gunmen separate non-Muslims from the group and killing them.
Kenya has seen a series of attacks since 2011, when it deployed military forces to Somalia to help fight the Shabab as part of a United Nations-backed African force, AMISOM. The extremist group, which is fighting the Somali government, has been driven from almost all of the country's major towns and has lost significant territory in recent years, but it is still able to mount devastating attacks in Somalia and Kenya. It says its attacks in Kenya are in revenge for that country's military actions in Somalia.
Last year the group attacked the upscale Westgate shopping mall in Nairobi, killing at least 67 people.
It has recently focused on attacks in coastal and northern territories, undermining one of Kenya's most important industries: tourism. The nation's beach resorts remain deserted after the fatal shootings of two foreign tourists in recent months.
Just as Nigeria, the continent's richest country, has lost northeastern territory to its homegrown extremist group, Boko Haram, Kenya has seen increasing attacks in its remote northern areas.
Kenya last week said it bombed a Shabab base and killed about 100 fighters after the bus attack.
The attacks in northern Nigeria are part of Boko Haram's fight to establish a strict Islamic state in the nation of 170 million people, split between a predominantly Muslim north and mainly Christian south.
Militants believed to be from Boko Haram have recently slain dozens of fishermen in the northeast of the country; attacked villages and towns; twice launched suicide bombings in a Maiduguri market, just days apart; and carried out multiple bombings and shootings at the central mosque in the northern city of Kano, killing at least 100 people.
Though the Shabab and Boko Haram are waging separate campaigns, analysts suggest that the groups have shared tactics. Boko Haram fighters are also believed to have been trained by Al Qaeda-linked groups in various parts of the continent.