MAPUTO (Reuters) - Mozambique's army launched a retaliatory attack on the mountain headquarters of the opposition Renamo movement on Friday, a day after a rebel ambush in which seven soldiers were killed, senior Renamo and government officials said.
The assault on Renamo's hideout in the remote Gorongosa mountains started in the middle of the afternoon, Renamo Member of Parliament Ivone Soares told Reuters after being granted safe passage by police through the front line.
A police commander in the central Sofala province said "lots of injured" were being taken to hospital after the worst flare-up in a year of tensions between government forces and Renamo, a guerrilla movement that waged a 1975-1992 civil war.
There was no other information on the number of casualties.
The fighting, a month before municipal elections that Renamo has vowed to disrupt, is likely to unnerve foreign mining investors in the southern African nation, which has recently discovered vast coal and off-shore gas reserves.
Mozambique has been one of Africa's fastest-growing economies in the last three years, largely because of huge mining investment, although the simmering insurgency has cast a shadow over the boom.
Renamo raids in April and June in the central province of Sofala killed at least 11 soldiers and police and six civilians, and forced a temporary suspension of some coal exports to the coast by rail.
Road traffic and the tourist trade were also affected.
A million people are thought to have died in the civil war that followed Mozambique's independence from Portugal and the fighting has made many people nervous, even though analysts say a slide into all-out conflict is remote.
Renamo was formed as an anti-communist rebel group in the 1970s by the secret service of white-ruled Rhodesia, and has been the main opposition to the ruling Frelimo party, a former Marxist movement, since the end of the war.
Analysts say this year's violence is a reaction to Renamo being pushed into political and economic obscurity by Frelimo, which is expected to dominate November's municipal elections and a nationwide poll in just over a year.
Major foreign mining investors include Brazil's Vale and global giant Rio Tinto.
(Reporting by Manuel Macari; Writing by Ed Cropley; Editing by Robin Pomeroy)