Suspected Al-Shabaab militants have burned down a school and abducted two teachers in an overnight attack in Fafi, Garissa.
The militants, armed with small arms and explosions, also vandalised a mobile communication mast in the area.
The attackers destroyed telecom masts during their attacks to disrupt police communication.
Northern and coastal Kenya have experienced a sharp rise in attacks linked to the Somalia-based terror group, in which security officers have been killed and security equipment destroyed.
The attacks came hours after nine security officers and a civilian died on Wednesday when their vehicles ran over explosive devices in separate terror incidents in Lamu County.
The first explosion happened at 8.30am, between Baure and Milimani, killing all seven police officers on board an armoured vehicle and the civilian passenger.
The officers from the Rural Border Patrol Unit of the Administration Police were travelling on the Kiunga-Hindi road.
Military reinforcements were immediately dispatched and were heading to the scene when another explosive went off along their way, killing two Kenya Defence Forces soldiers and injuring another.
Yet another explosive device went off between Kiunga and Ishakani later at 3pm.
Initial investigations show the third explosion was aimed at a military lorry but it went off just before the vehicle arrived at the spot.