Voters queued at polling stations as election officials processed ballots across the country.

Under the proposed constitution, Guinea-Bissau would move away from its current semi-presidential system towards a stronger presidency.

The president would gain greater authority over the prime minister and government, including powers to appoint and dismiss the prime minister and dissolve parliament. The National People's Assembly would also be reduced from 102 seats to 65.

Voter Jamil Yala backed the proposed changes and called for widespread participation in the referendum.

"The new generation is at the right age to assume the leadership of the country," he said, adding that the people should support the referendum in order to "regain our constitution" and ensure it belongs to all citizens.

The opposition PAIGC has strongly contested the referendum and urged voters to stay away from the polls .

The party argues that the proposed changes would concentrate too much authority in the presidency while reducing the powers of parliament and the prime minister.

The referendum comes nine months after the military seized power following disputed presidential and legislative elections.