The explosion appeared to be minor and one of the officials said if it turns out to be an explosive device planted by insurgents it may have been improperly wired. The two officials spoke on condition they weren't identified.
Somali insurgents have laid land mines along the Kenyan border previously, but there has never been such an incident in the refugee camp -- Dadaab -- before. Dadaab houses nearly 500,000 refugees, mostly Somalis, tens of thousands of whom have arrived in recent months because of Somalia's famine.
The latest explosion will add to the security concerns of aid groups operating in Dadaab. Last month two international staff were kidnapped from Dadaab by Somali gunmen.
Also Saturday, a military official said the tempo of Kenya's military pursuit of Al Qaeda-linked militants in Somalia has been slowed by the needs of hunger-stricken Somalis.
Col. Cyrus Oguna said that the Kenyan army is assisting desperate Somalis who need food and medicine in areas the Islamist group al-Shabab occupied but withdrew from as Kenya forces marched into Somalia in mid-October.
"You cannot move when the people you want to assist have problems," he said. "We need their support."
The U.N. says hundreds of thousands of Somalis could die because of the region's famine, which has hit hardest in areas that al-Shabab controls. Oguna said the humanitarian agencies that were blocked by al-Shabab from supplying relief to famine stricken Somalis can now deliver the aid because the area is secure.