President Mwai Kibaki introduced an indefinite dusk-to-dawn curfew in Tana River County and ordered additional security deployed. Nine police officers were among those killed.

"The killings of innocent women, children, men and security officials is a heinous crime, and the perpetrators must be punished accordingly for their outright disregard for the sanctity of human life and property," a statement from Kibaki's office read.

The provincial commissioner said police arrested 15 last week. He called for an increased military presence.

'Getting dangerous'

Pokomo farmers and Orma pastoralists occasionally clash over access to land and water. The current violence broke out after Pokomo accused Orma of illegally grazing cattle and massacred more than 50 Orma villagers.

"The situation is getting dangerous," Kenya Red Cross chief Abbas Gullet said in a statement. "Something needs to be done urgently."

The Red Cross announced that it had sent ambulances, paramedics and first-aid teams into the village and that eight people were still in hospital.

Ethnic clashes have killed more than 200 Kenyans since January, 109 of them in the current wave of attacks. Tribal violence has also plagued recent elections, including 2007 and 2008 clashes that killed more than 1,000.

mkg/mr (AFP, AP, dpa, Reuters)