The Latest: American, Canadian detained ahead of Kenya vote

Orengo says the detentions occurred at around the same time that armed and masked police raided an opposition vote counting center, intimidating workers and seizing equipment.

Kenya's presidential candidates are diving into a final day of campaigning before Tuesday's narrowly contested election as many worry that the vote could turn violent.

The torture and killing in recent days of a key election official in charge of the electronic voting system has some concerned about the possibility of vote tampering.