Kenya's eight presidential candidates held the country's first ever face-to-face debate on Monday as tensions mount ahead of next month's election, five years after bloody violence erupted in the wake of the last vote.

While two main candidates -- Uhuru Kenyatta and Raila Odinga -- dominate the race for the March 4 election, all the hopefuls have potential influence, especially if voting goes to a second round run-off.

Six people, including three police officers, have been shot dead in a cattle theft raid in northwestern Kenya, a local police chief said Monday.

"The three officers were ambushed as they pursued stolen animals. Three locals were also killed in the raid," area police chief Omondi Musewe said.

A suspected suicide bomber in Kenya died when his explosives blew up before he reached his apparent target, wounding three passers by, police said Sunday.

The incident occurred in the northeastern town of Wajir late Saturday.

At least eight people were killed and several wounded in the latest outbreak of violence in the Tana River region of southeast Kenya, where scores died in repeated clashes last year, police said Wednesday.

"Eight people have been killed and houses burnt," a senior police officer told Agence France Presse on condition of anonymity, adding that nine others were wounded and had been taken to hospital.

Four people, including three police officers, were wounded when a grenade was hurled at a police vehicle Monday in the northeast Kenyan town of Garissa, close to the Somali border, a police source said.

"A total of four people have been injured. Three are administration police," a Kenyan paramilitary police unit, a police officer in Garissa told Agence France Presse on condition of anonymity.

At least 39 people were killed on Friday in an attack on a village in a remote part of southeastern Kenya's coastal region, where deadly tribal violence also erupted earlier this year, police said.

The raid on Kipao village in the Tana river delta in the early hours "unleashed terror" on the inhabitants, police said.

Tens of thousands of refugees living in urban areas in Kenya must return to remote and overcrowded camps, the government said Tuesday, demanding all aid be cut off outside the camps.

"All asylum seekers and refugees from Somalia should report to Dadaab refugee camps, while asylum seekers from other countries should report to Kakuma refugee camp," an official statement printed in national newspapers read.

A huge blast shook the predominantly Somali neighborhood of Eastleigh in the Kenyan capital Nairobi Sunday evening, police said.

"There has been an explosion in the area. We do not have any more details currently about the nature of the explosion or whether there are casualties involved," area police chief Moses Nyakwama told Agence France Presse.

One of Kenya's best known private game reserves in Kenya announced Friday a plan to fly unmanned surveillance drones to monitor and protect critically endangered rhinos from rampant poaching.

Ol Pejeta, a 90,000-acre non-profit private wildlife conservancy in central Kenya's Laikipia District, holds four of the world’s last remaining seven northern white rhinos.

Three people were killed and eight wounded in a blast outside a mosque in the Kenyan capital, the Kenyan Red Cross and police said Friday.

There were "three fatalities" as well as several wounded, some critical, a Red Cross official said after the "explosion near a mosque in Eastleigh", a largely ethnic Somali district of Nairobi.