Opposition supporters in Brazzaville, Congo
Supporters of opposition candidate Guy Brice Parfait Kolelas celebrate his second-place finish at the party's headquarters in Brazzaville on March 23, 2016MARCO LONGARI/AFP/Getty Images

The town of Madingou in the Republic of the Congo has been the theatre of confrontations between security forces and protesters who set a police station ablaze in anger over the death of a teenager.

Tensions had been running high in the Central African nation, also known as Congo-Brazzaville, where simmering anger against President Denis Sassou Nguesso, who this month extended his 32 years in power, seems to be boiling over.

Since the 20 March presidential election, there have been reports that government-sandctioned security operations had been conducted in the department of Pool - south of the capital - against former members of the Ninja militia and its former leader, Frédéric Bintsamou (nicknamed Pasteur Ntumi). The government also carried out operations against opposition leaders and supporters, who allegedly attacked a police station and neighbourhoods in southern parts of the capital, Brazzaville, on 4 April.

Killing of 13-year-old Japhet Nguembo

Confrontations in Madingou, capital city of the southern Bouenza Region, followed the death of 13-year-old Japhet Nguembo, who was allegedly shot by security forces near the town's station on 26 April. According to local sources, the teenager later died of his injuries.

Local media described how the city had been "on the edge" after youths reacted to the killing by setting the station's police headquarters ablaze.

A young resident, Ben-Garcia (whose name has been changed), explained "a drunk policeman shot at a schoolboy, who had apparently promised to fight his son at school. Following this, a part of the police station was set on fire by angry parents, and the policeman was arrested".

A number of commentators have warned the teenager's death may be used for political point-scoring by the opposition, who have accused the government of targeted killings. However, other observers have said the incident was not politically-motivated. Residents firmly condemned Nguembo's death.

'Deeply concerning' reports of attacks

The United Nations (UN), meanwhile, said it was "deeply concerned" about reports security operations undertaken in the Pool allegedly resulted in attacks against civilian targets and displacement of the population from the affected areas.

Stéphane Dujarric, spokesman for the UN Secretary-General Ban Ki-Moon said he was "troubled about restrictions on access to the region, which hamper adequate information gathering, evaluation and reporting on the situation".

Condemning all acts of violence, Moon also urged the government to ensure that humanitarian and other relevant parties are granted access to the affected areas and population, and that security forces act in compliance with the country's obligations under international human rights law.

Congo Republic President Denis Sassou Nguesso
Congo Republic President Denis Sassou Nguesso speaks during a news conference in January 2015.REUTERS/Anis Mili