Mozambique's main opposition party Renamo on Monday boycotted peace talks with the ruling Frelimo for the second time, raising tensions further in the southern African nation where sporadic clashes between the army and rebel gunmen have resumed.

"As long as we do not have clear indications that the government is ready to accept our proposals, discussions are useless," Renamo MP Eduardo Namburete told AFP on Monday.

Peace talks were introduced two years ago after Renamo began a low-level insurgency against the government, two decades after its devastating 16-year civil war with Frelimo ended.

Former President Armando Guebuza and Renamo leader Afonso Dhlakama last year signed a ceasefire in Maputo, allowing Dhlakama to run in the October presidential election.

But one year and 114 rounds of dialogue later, the ceasefire still hasn't been fully implemented, with Renamo blaming the government's failure to integrate rebel soldiers into the army and police.

Last week, Dhlakama announced the creation of a separate Renamo police force, and in recent weeks the opposition party also announced the creation of two new military bases.

Low-key skirmishes between Renamo and the military have resumed in recent months in the central coal-rich Tete province, forcing some to flee to neighbouring Malawi, according to local reports.

"We are concerned by the increasing levels of tension," peace talks mediator Reverend Anastacio Chembeze said in Monday's edition of the state-sponsored Noticias daily.

Mediators believe only a high-level meeting between the president and the Renamo leader will defuse the tension, but Dhlakama has officially rejected invitations sent by the presidency.

"If it is only to sit and drink tea, then there is no reason for them to meet. The government must first comply with the ceasefire before any meeting to take place," Renamo spokesperson Antonio Muchanga told AFP.

On Saturday, Dhlakama escaped unhurt after his convoy was hit by gunfire as he returned from a rally in the central Manica province.

He declared it a "planned attack" by Frelimo, an accusation which the police denied.