Police in Papua New Guinea have shot a young mother dead at a polling station in the capital, Port Moresby, in the latest violence to mar national elections, according to reports.

Homicide detectives are investigating the fatal shooting which occurred on Monday, a police statement said.

Annaisha Max, 22, was holding her one-year-old son when she was shot, the Australian Broadcasting Corp (ABC) reported.

“They (police) came with force, excessive force. It was unprovoked,” Emmanuel Kiangu, a community leader who was on the scene, told ABC.

Police gave no warning they would open fire, according to Max’s friend, Anna Koip.

“They didn’t even say a word. They switched their guns to auto and fired into the crowd, where a lot of us were waiting to vote,” Ms Koip said through a translator.

Since voting began on July 4, fights between rival groups have broken out over allegations of vote-fixing.

Prime Minister James Marape has apologised to thousands of people who have been turned away from polling stations because of problems with the electoral roll.

The crowd on Monday reportedly became agitated after waiting hours for voting to begin.

A group gathered around police cars asking where the ballot boxes were. Police called for reinforcements before the shooting started, ABC said.

Police Metropolitan Superintendent Gideon Ikumu said in a statement on Tuesday that police reinforcements were sent to “restore order when a rowdy and quarrelsome crowd threatened to harm election officials and disrupted polling”.

“Rocks were hurled at police and gunshots were fired to disperse the unruly crowd,” Mr Ikumu added.

He said he had personally assured angry residents after Ms Max’s death that a police investigation would “establish how the victim was killed and who was responsible for her death”.

“Homicide detectives are now collecting evidence including video footage and statements from potential witnesses,” Mr Ikumu said.

Ms Max died in an electorate where polling had been delayed three times.

A spokesman for Transparency International, a global movement to end corruption, said the election risked failing.

“Unfortunately, it hasn’t been a successful and peaceful and safe election,” he said.

“But I encourage all of our stakeholders out there, particularly the candidates and their supporters, to support the process, try and conclude the elections the best we can.”

Polling lasts weeks and the composition of the new government – with more than 50 parties contesting 118 seats – will not be known until parliament next sits in August.

The top contenders to lead the new government are Mr Marape and his predecessor, Peter O’Neill, who resigned in 2019.

Since Papua New Guinea’s independence from Australia in 1975, elections in the nation of nine million have been marred by violence, fraud and bribery.

At the outset of voting, police urged citizens not to sell their votes to any of the 3,625 candidates vying for election. Candidates in Papua New Guinea routinely pay poor constituents to vote for them.

Papua New Guinea is a diverse tribal society of mostly subsistence farmers with more than 800 languages.