A senior security official in Kenya has accused opposition leaders of inciting riots and attacks on police that have occurred in some opposition areas since a repeat presidential election.

Martin Kimani, a presidential envoy on terrorism, told foreign journalists on Sunday that the unrest has been "couched as demonstrations" and "emanated from political speech" by opposition leader Raila Odinga and senior aides.

Without providing details, Kimani also said security forces are looking for some "politicians" allegedly linked to the recent unrest. He also denied opposition allegations that security forces are engaging in a systematic campaign to violently target opposition supporters.

At least six people have died in violence linked to Thursday's election, which was a rerun of an August vote that was nullified. Some were shot by police.