At least eight Kenyan police officers died after their car hit a roadside bomb near the Somali border.
Eleven people were in the car when they hit the device in the east of the Wajir district. The fate of the others is unclear.
Nobody admitted to have planted the explosive.
Unnamed officials told AFP that police have prosecuted alleged al-Shabab Islamists who are fighting Somalia's government and its supporters, including Kenya
The Al Qaeda group has been trying for years to defend the Somali government to overthrow.
The insurgents have lost many of their strongholds, including the territories of the Somali capital, Mogadishu.
However, they control large rural areas of Somalia and continue to wage guerrilla warfare against local authorities.
Al-Shabab has also committed Several attacks and kidnappings in Kenya, with a reward for the country's participation in Anisom ̵
In a separate incident, at least eight people were killed by a bomb exploding at a checkpoint near Somalia's parliament in Mogadishu.
Al-Shabab said she carried out the attack and another on a road to the city's airport where no one had died.