Kenya's Deputy President William Ruto says the government has given the United Nations High Commission for Refugees three months to close a refugee camp and send the 400,000 Somalis living there back to their country.

The Kenyan government says the Dadaab refugee camp in eastern Kenya has become a recruitment center for the extremist group al-Shabab whose gunmen last week killed 148 people at the country's Garissa College University.

Ruto said in rally on Saturday that Kenya must be secured at all costs.

Kenyan President Uhuru Kenyatta vowed a sharp response to last week's attack at the university. Kenyan warplanes attacked suspected militant positions in Somalia, and the government said Wednesday that it was freezing accounts of organizations and individuals suspected of financing Islamic extremists.