This was a revenge attack for the Kenyan actions against the Somali jihadists in 2011. The headline says two policemen were killed, while the lead sentence of the article says four. “Islamist militants blamed in deaths of two police officers in Kenya,” from the Columbus Dispatch, August 18:
Four Kenyan police officers were fatally shot in the border county of Garissa when 40 heavily armed men, suspected of belonging to the Somali militant group al-Shabab, attacked a police post, a government official said yesterday.
The eastern African nation, which sent troops into Somalia in late 2011 to pursue the al-Qaida-linked militants, has suffered a string of gun and grenade attacks claimed by al-Shabab as retaliation.