Mozambique's defence minister threatened Tuesday to send in the military to halt weeks of deadly post-electoral protests he said were aimed at overthrowing the government.
Rights groups said security forces killed at least 18 people in protests since an October 9 vote won by the ruling Frelimo party.
The opposition rejected the results and led several waves of protests in the southern African nation, most of which were dispersed by the police.
"Violent demonstrations are sowing hatred between brothers, destroying infrastructure and showing how divided we are," Defence Minister Cristovao Chume said at a press conference.
"There is an intention to change the democratically established power," he said.
"If the escalation of violence continues, the armed forces will have to protect the interests of the state."
The warning came ahead of a protest called for Thursday in the capital Maputo by leading opposition politician Venancio Mondlane, who has dubbed it "the day of Mozambique's freedom".
Since the election, Mondlane has used social media to rally supporters out on the streets to protest against results he has labelled fraudulent.
Security forces have killed at least 18 people in crackdowns on protests since the vote, including seven people at the weekend, Human Rights Watch told AFP Tuesday in an updated tally.
Chume confirmed the death of a police officer at a protest in Matola at the weekend whom he said was stoned to death by a mob.
Election observers, including from the European Union, have noted serious flaws before, during and after the vote, with the electoral body accused of manipulation to keep Frelimo in power.