Police in Mozambique said Friday they were investigating reports of the discovery of a mass grave containing 120 bodies in a region which has seen clashes between the security forces and rebels.

Local media reported Thursday evening that farmers in the central Gorongosa region had found a communal grave containing the bodies of villagers.

A representative of Renamo, the rebel group that fought a 16-year war against the state ending in 1992 and later became an opposition party, confirmed the find to AFP.

A police spokesman in the capital Maputo said a commission had been set up to search the area in question but that "at this preliminary stage, nothing has been found."

Police spokesman Inacio Dina added that no resident had come forward to the police with any information as yet.

The Renamo official, who spoke on condition of anonymity, said the grave was located in Canda, near Gorongosa National Park, in a zone known as "76".

"The grave contains 120 bodies," he said, adding some were "in an advanced state of decomposition."

The Renamo member said the area was close to the place where Renamo leader Afonso Dhlakama is believed to have gone into hiding in October 2015.

Dhlakama contested the results of October 2014 presidential and legislative elections, which were won by Frelimo, the movement which led the country to independence from Portugal in 1975 and has ruled ever since.

Tensions between the security forces and Renamo members intensified in December after Dhlakama announced plans to take power in six of the country's 11 provinces.

A spokesman for the UN High Commissioner for Human Rights in Geneva said Friday the agency had "received worrying information about ongoing armed clashes in Mozambique between national security forces and members of Renamo."

Rupert Colville said the security forces in the southern African nation had been accused of "summary executions, looting, destruction of property, rape, ill-treatment, and other human rights violations" and that "at least 14 local Renamo officials" had been reported killed or abducted since the beginning of the year.

The UN refugee agency UNHCR said the unrest had prompted more than 10,000 people to flee their homes to neighbouring Malawi over the past four months.