MOMBASA, Kenya (Reuters) - The death toll in Kenya's restive coastal region rose to at least 17 on Monday in two attacks on police by machete-wielding men hours before voting began in a tense presidential election, police officers said.

The authorities suspect at least one of the attacks was carried out by members of a coastal separatist group who had threatened to disrupt voting if their demand for secession of the Indian Ocean coastal strip was not met.

Senior police officers said the death toll was comprised of nine security officers, two civilians and six attackers.

(Reporting by Joseph Akwiri; Writing by Richard Lough; Editing by Edmund Blair)