UN Secretary-General António Guterres has appealed for calm in Mozambique following the killing of two opposition figures amid a dispute over elections held earlier this month, calling for a probe into the killing.

Elvino Dias, legal advisor to presidential candidate Venâncio Mondlane, and Paulo Guambe, the legal representative of the political party PODEMOS, were gunned down in the capital, Maputo, on Friday night.

PODEMOS rejected provisional results of the October 9 presidential elections, which showed that the FRELIMO party, which has ruled Mozambique for nearly 50 years, was in the lead.

Guterres urged the authorities to investigate the killings and bring the perpetrators to justice swiftly.

He called on all Mozambicans, including political leaders and their supporters, to remain calm, exercise restraint and reject all forms of violence before officially announcing the electoral results.

He also reaffirmed the UN’s unwavering support for peace and stability in Mozambique during this important phase in the country’s history.

In a related development, Mozambique police on Monday fired teargas and bullets at protesters in the capital Maputo who had gathered at the scene where two opposition party figures were shot dead on Saturday after a disputed election.

A Reuters witness saw some police officers firing handguns while dispersing the crowd.

Adriano Nuvunga, director of Mozambique’s Centre for Democracy and Human Rights, said that bullets hit two journalists and a security guard but not seriously wounded.

A police spokesperson could not immediately be reached for comment.

The full results of Mozambique’s October 9 national election are expected this week, with early results showing that the ruling party Frelimo is set for another win.

Opposition candidates say the poll was rigged.

Frelimo has ruled the southern African country since 1975 and has been accused of electoral fraud by opposition leaders, civil society and election observers, which it denies.

Mozambique’s electoral commission has declined to comment on accusations of fraud.

U.S.-based observers said the poll did not meet international standards for democratic elections, noting reports of vote buying, intimidation, inflated voter rolls and other issues.