Mozambique votes on Wednesday in a tense general election highly likely to deliver victory to the ruling party, Frelimo, which has governed the Southern African nation since 1975.

Four candidates are vying to replace President Filipe Nyusi, who is stepping down after serving two terms. The favourite is Daniel Chapo, 47, a lawyer viewed as a safe choice for business and a fresh face for the long-ruling party.

He faces Venancio Mondlane, a charismatic independent candidate who draws huge crowds, former rebel commander Ossufo Momade, and a small opposition party leader, Lutero Simango.

Dozens of posters of Chapo's face were pasted along Maputo's palm tree-lined seaside promenade, and red Frelimo flags flew over streets flanked by high rises dispersed with Portuguese colonial buildings. No opposition poster was in sight.

Poverty is the major concern of Mozambique's 35-million people, about half of them registered to vote. An Islamist insurgency in the north that has forced thousands to flee their homes and halted multi-billion dollar gas projects also weighs.

"The next president must create jobs. We are tired of hearing promises," said Amandio Sergio, 32, a small business owner in the seaside capital.

Frelimo first allowed elections in 1994 and has since been accused of rigging them, which it denies. Rebel force turned-opposition party Renamo usually comes a distant second.

Mondlane poses a challenge to both this year, but lacks the machinery of established parties and may struggle to win votes in rural areas, analyst Dercio Alfazema said.

"This election is different because we have new actors ... (but) Frelimo has a big probability to win," Alfazema said.

Chapo has experience in local government but has not been tainted by Frelimo's corruption scandals, he added.

Counting will start after the polls close at 6 pm (1600 GMT), although it can take up to two weeks for official results.

A disputed outcome would likely trigger protests, which broke out after Frelimo swept last year's municipal elections and were forcefully suppressed.

Apathy may dampen them, however.

"I feel it doesn't make any difference," 26-year-old fisherman Mussa Issufo said of the poll.

"Nothing ever changes."