((Photo: AP)

The murder of a key local election observer in Mozambique a week before the presidential vote has caused an outcry, especially after police confirmed on Tuesday that several of the suspects were police officers.

“This is a serious — and chilling — escalation of election violence,” Human Rights Watch researcher Zenaida Machado said on Twitter.

Anastácio Matavel was shot dead Monday morning after leaving a training for national election observers in southern Gaza province. A police spokesman, Orlando Mudumane, confirmed to the Portuguese news agency Lusa that the four officers worked in special operations and that their commanders had been suspended.

The European Union election observer mission, one of several international observers, strongly condemned the murder. It also noted that violent clashes between political parties in the southern African nation have continued throughout the campaign “without a strong, clear and persistent condemnation” from the government or party leaders.

Mozambique’s presidential election is Oct. 15 and President Filipe Nyusi with the ruling Frelimo party seeks a second five-year term. The vote comes just two months after Nyusi and the opposition Renamo party signed a permanent cease-fire meant to stop the fighting that has flared sporadically in the 27 years since the end of a 15-year civil war that killed an estimated 1 million people and devastated the former Portuguese colony.

This election is expected to be especially challenging, even beyond the political tensions that in the past have led to violence.

Large parts of Mozambique are struggling to recover from a pair of cyclones that struck the central and northern regions earlier this year and killed more than 600 people, while attacks by shadowy extremists in the north are the source of growing concern. In recent months the Islamic State group has claimed it was behind some of the attacks.

This vote is considered crucial because a recent constitutional amendment decentralized power so that provincial governors will now be elected directly, rather than appointed by the central government. It was another measure aimed at easing political tensions.

Pope Francis in his visit to Mozambique early last month praised both main political parties and all Mozambicans for their courage in setting aside personal interests and violence to work instead for the common good, and he urged a continued commitment to reconciliation.