Concurrently, the Kenyan army fought the Shifta War against ethnic Somali rebels inhabiting the Northern Frontier District who wanted to join their kin in the Somali Republic to the north. A ceasefire was eventually reached with the signature of the Arusha Memorandum in October 1967, but relative insecurity prevailed through 1969. To discourage further invasions, Kenya signed a defence pact with Ethiopia in 1969, which is still in effect.