An attack on a civilian vehicle near the Kenya-Somalia border has killed four people, according to early reports.
Kenya's Red Cross told the Associated Press that rocket-propelled grenades and machine guns were used in an attack on a bus in northeastern Kenya, near the borders of Somalia and Ethiopia.
Kenya has sent troops into Somalia to hunt al Qaeda-linked Al Shabaab militants, following a wave of kidnappings of foreign tourists and aid workers in Kenya. Al Shabaab has threatened retaliatory attacks.
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A police spokesman told Reuters that an attack was reported about 70 miles from Mandera town in northeastern Kenya. The vehicle was said to be carrying government officials.
The AP says the vehicle which carrying school examination papers.
On Monday there were two grenade attacks in Nairobi, Kenya's capital, killing one person and injuring more than 20.
A Kenyan man who was arrested after the grenade attacks admitted in court Wednesday that he participated in one of the attacks and is a member of Al Shabaab.
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