Mozambique security forces detained three soldiers for ambushing and robbing foreign travellers on a main highway, the defence ministry said Monday.

"The three military suspects are held in Gorongosa pending further investigation and prosecution," defence ministry spokesman Amelta Muiquija said in a statement.

The soldiers masquerading as a former rebel group attacked civilian vehicles in central province Sofala early Saturday morning, one of their victims told independent newspaper O Pais.

"They said they were Renamo fighters and demanded we give them everything of value we had with us," a unnamed victim said.

After the attackers drove off with around $1,000 in cash and other goods, the victims reported the case to the nearest police station.

The victims identified the culprits in an identity parade, according to the newspaper.

The robbery happened on the same day armed forces attacked a smaller Renamo camp near where gunmen killed two civilians in raids on the main north-south highway in June.

Simmering tensions between Renamo, which is also the official opposition, and the Frelimo-led government erupted in violent clashes again in April -- over two decades after a bloody civil war ended.