Mozambican government forces attacked a guerrilla camp of the Renamo opposition group in a flareup of violence ahead of local and presidential elections between former foes from the country's devastating 17-year civil war.
Sporadic bloodshed this year has raised fears that Mozambique, one of Africa's fastest-growing economies with major foreign investors developing its huge coal and natural gas deposits, could slip back into open conflict.
The latest clash occurred at the weekend in the Muxungue district of Sofala province, scene of other confrontations this year between armed supporters of Renamo chief Afonso Dhlakama and the security forces of the Frelimo government.
Dhlakama has demanded reforms, including changes to an electoral system he calls biased, from President Armando Guebuza. Local elections are to held in November with a presidential vote due in 2014 in the former Portuguese colony.
Interior Ministry spokesman Pedro Cossa told reporters in Maputo that one soldier was killed and another injured in the weekend assault on the Renamo camp at Pandje. Cossa said he had no information about Renamo casualties.
Renamo spokesman Fernando Mazanga put the government death toll at 26 and said the guerrillas had suffered no losses. He added that 37 soldiers and police were wounded.
No independent witnesses were available to reconcile the conflicting claims.
Big investors include Italy's ENI group, which said on Tuesday it had agreed to pay $400 million tax on the $4.2 billion sale of a Mozambique gas field stake to China and also build the east African country a power station.
Renamo raids in April and June in Sofala killed at least 11 soldiers and police and six civilians, forcing a temporary suspension of some coal exports to the coast by rail, reducing road traffic and causing tourist cancelations.
Renamo was formed as an anti-communist rebel group in the 1970s by the secret service of neighboring Rhodesia in retaliation for Mozambique sheltering guerrillas fighting the white-minority government of what is now Zimbabwe.
Renamo was later adopted by the apartheid-era South African military but stopped fighting under a 1992 peace pact to become Mozambique's leading opposition party.
Since 1992, Dhlakama's party has lost successive elections to Frelimo that he has attributed to fraud. Dhlakama and a group of his guerrilla veterans in October went back to his former jungle civil war base in the Gorongosa region.
He said he feared for his safety.
Cossa said government forces were trying to restore order in the wide area around Dhlakama's camp.
Both sides have said they do not want war and have continued to negotiate over Renamo's demands for a more balanced electoral body and the integration of its fighters into the army and the police.