One person was killed and six were wounded by gunfire Thursday, a local health official said after troops in Benin cleared protesters in a flashpoint town three days before presidential elections.

Opponents to President Patrice Talon had blockaded a major highway in the central town of Save before troops fired tear gas and shots in the air to disperse them, an AFP reporter at the scene said.

"We admitted them at our clinic... One dead from a live round and six with bullet wounds," said Jose Godjo, director of the Boni clinic in Save. "All the wounded have been transferred to a hospital in Save."

Benin goes to poll on Sunday in a presidential ballot critic say is already tilted in President Patrice Talon's favour after a crackdown on opponents.

A cotton tycoon first elected in 2016, Talon faces two little-known rivals with most opposition figures from the West African country either living in exile or disqualified from running in the election.

Protests broke out this week in several towns, mainly in opposition strongholds, as tensions built before Sunday's vote with young demonstrators blocking roads and ransacking pro-government property.

Once praised as a vibrant multi-party democracy in an often troubled region, critics say Benin has slipped into authoritarianism under Talon as his political foes were steadily sidelined.

Slotted between Africa's powerhouse Nigeria and tiny neighbour Togo, Benin has seen some economic successes in five years under Talon, with improved roads, water and energy supplies. But analysts say its pluralist politics are now dimmed.

Talon has played up his economic programmes while campaigning. At the start of the pandemic, he said he could not enforce public confinement because Benin lacked the means of rich countries.