MAPUTO — Mozambique opposition party Renamo, suspected of killing two civilians last week in a nascent guerrilla campaign, said on Friday it regretted disruption of the economy and called for more dialogue with the government.

Two decades after the end of a long civil war, Renamo,, which was founded in the 1970s with the help of apartheid South Africa to counter the Marxist Frelimo, is stepping up pressure on the ruling Frelimo party, sparking concern a return to violence could derail Mozambique’s commodity-fuelled economic boom.

Eleven soldiers and policemen and five civilians have been killed since April in attacks blamed on Renamo.

Although Renamo is not large enough to manage a widespread guerrilla campaign, it is estimated to have 1,000 men under arms and analysts say it could cause enough trouble to upset the foreign mining investment boom.

Global miner Rio Tinto this week suspended coal shipments from northwest Mozambique after the former guerrilla group threatened to disrupt the Sena railway used to move coal to the Indian Ocean.

"We want to see more investors coming into Mozambique but the current moment of political tension does not permit this," said spokesman Fernando Mazanga, adding the party "lamented" the disruption to growth in the former Portuguese colony.

"That is why we want to accelerate the talks with the government."

Last week gunmen killed two people in ambushes on vehicles.

Renamo also called for increased dialogue and condemned the movement of troops and weapons towards the centre of the country, which it said targeted its leader Afonso Dhlakama, who has operated from his base in the remote Gorongosa Mountains since November.

Renamo has previously backed out of talks. In April it rejected the government’s offer for talks, saying the proposed location — a luxury hotel in the capital — was "not dignified enough for the importance of the meeting".

The Ministry of Defence could not confirm an increase in troops or weapons in the central part of the country.

"The military is always in motion. There is no space that can be free from the authority of the government," said Benjamin Marco, a spokesman for the ministry.