Ouagadougou - Voters in the West African state of Burkina Faso began heading to the polls on Sunday to choose a president, with incumbent Blaise Compaore widely expected to be returned to power.

Polling stations opened at 6am in the capital city Ouagadougou and elsewhere around the country, with 3.9 million people registered to turn out to pick a president from 12 candidates.

Compaore, in office for 18 years, is standing for a third time in one of the poorest countries of Africa, where half the population lives beneath the poverty line.

Chosen as the candidate of the powerful ruling Democracy and Progress party (CDP), Compaore, 54, has served two seven-year terms since the reintroduction of multi-party elections in 1991.

About 1,000 foreign observers are on hand to monitor voting. The opposition has accused the president's camp of preparing to rig votes, claiming there were plans for "massive electoral fraud" by the regime.