A manhunt is underway in the Philippines after two motorcycle-riding men shot and killed a New Zealand tourist in a daytime street robbery – which officials fear could scare foreign holidaymakers away.

Nicholas Peter Stacey, 34, was hit once in the chest while trying to wrestle a pistol from one of the men who held him and his Filipina girlfriend up in Manila’s Makati financial district on Sunday, police major general Jonnel Estomo said.

“We regret to report this incident and extend our sympathy to the bereaved family,” Mr Estomo said in a statement, adding he has ordered the police to “leave no stones unturned until the culprits are brought to jail and are prosecuted”.

While he described the deadly street robbery as an “isolated incident”, Mr Estomo acknowledged it has the potential to frighten foreign tourists. Police patrols will be beefed up to prevent a recurrence, said Mr Estomo, who heads up the Metropolitan Manila police.

“We know that this incident could spark fear among tourists who plan to visit our country, so we will make sure the slain victim will get justice and demonstrate that the police are always ready to provide service,” Mr Estomo said in a statement.

The victim’s girlfriend, Pamela Gaye Villanoza, told investigators she and Mr Stacey had just arrived in the capital region from a trip to the western island province of Palawan and were walking to a laundry shop in the early hours when the suspects approached on a motorcycle.

One of them got off and pointed a pistol at the couple while his companion parked the motorcycle a few metres away. Mr Stacey grappled with the armed man and was shot, she said.

Before fleeing, the gunman, who was wearing a black shirt and red athletic shorts, took Ms Gaye Villanoza’s mobile phone and wallet, police said.

Investigators will try to match a slug found in the area and compare it with slugs recovered from other recent crime scenes in the heavily populated metropolis to try to identify the suspects and assess how they work, police said.

Mr Stacey’s murder occurred amid high-profile gun attacks on two local politicians which underscore how violence – even against officials – has persisted despite the government’s pledge to combat it.

Gunmen wounded governor Mamintal Alonto Adiong Jnr of southern Lanao del Sur province and killed four of his bodyguards in an attack on their convoy on Friday.

On Wednesday, police said they had killed one of the suspects in a clash.

Separately, unidentified men reportedly wearing police uniforms fired guns at the van of northern Aparri town deputy mayor Rommel Alameda on Sunday, killing him and five companions in northern Nueva Vizcaya province. The suspects remain at large.

Crimes, decades-long Muslim and communist rebellions and other security concerns have long hampered tourism in the Philippines, a Southeast Asian archipelago offering white sand tropical beaches, diving and surfing resorts, heritage towns, rainforests and warm hospitality.