Flooding from heavy rains have killed at least 40 people in Mozambique and neighboring Malawi, where a state of natural disaster was declared Tuesday in nearly a third of the country.

In Mozambique, where some waters have risen to over double flood thresholds, a group of 25 school children was swept away by torrents Monday, and 18 others have been reported missing. 

Mozambique has elected Filipe Nyusi of the governing Frelimo party as the next president, the National Electoral Commission said Thursday in announcing final results of polls two weeks ago.

The former defense minister won 57 percent of the vote in the southern African nation -- sharply down on Frelimo's 75 percent victory in the last presidential election in 2009.

Military observers from up to nine countries will be deployed across Mozambique later this month, to ensure post-election tensions do not spell a return to violence.

Government minister Jose Pacheco said that details of the mission were still "a work in progress", but the deployment will begin on October 29.

Former Mozambique rebel leader Afonso Dhlakama pledged Saturday that his Renamo movement would not return to war despite disputing this week's elections.

"Violence is not necessary," he told a news conference, saying the southern African country had seen enough war.

Mozambique's ruling Frelimo party is likely to sweep hard-fought presidential and legislative elections, according to first results and unofficial projections released Thursday.

A partial vote count and projections by civil society groups suggested Frelimo's Filipe Nyusi will become the country's new president, winning around 60 percent, a huge drop from the 75 percent won by the party's candidate in the 2009 election.

Mozambicans voted Wednesday in a closely-fought test for the ruling Frelimo party, which has run the southern African country since independence from Portugal in 1975, with opposition parties crying foul.

Frelimo is facing growing discontent over a wealth gap that persists despite huge mineral resources, with fast economic growth sidestepping the bulk of a population that is among the world's poorest.

Mozambicans started voting Wednesday in a tough electoral test for the ruling Frelimo, the party that has run the resource-rich country since independence in 1975.

Voters in neat lines started casting their ballots shortly after 7:00 am (0500 GMT) with Frelimo facing growing discontent amid an apparent popular swing towards the opposition.

Mozambique's upstart opposition on Monday vowed to take on the two traditional political heavyweights by offering a non-violent alternative in polls taking place this week after a low-level conflict.

While the ruling Frelimo party and its main opposition rival Renamo have been at each other's throats during an insurgency that lasted nearly two years, the Mozambique Democratic Movement (MDM) has been quietly focusing on growing its support base.

Day-long fighting erupted between the supporters of Mozambique's ruling Frelimo and opposition party Renamo, as they concluded electioneering ahead of polls this week, police said on Monday.

Feuding between Frelimo and Renamo dates back to the southern African nation's almost 16-year-long civil war which ended in 1992. The two groups have had an uneasy relationship since.

Mozambique's charismatic opposition leader Afonso Dhlakama on Saturday said he was confident that the upcoming presidential election will be the country's first free vote, after he fought to have the electoral laws changed.

"I believe these are the first elections with credibility and even transparency, if everything goes according to the law," Dhlakama told AFP after a day of whistle-stop rallies in the capital.