Watch: Disturbing scenes of daylight robbery in Rio

Disturbing scenes of daylight robbery in Rio de Janeiro could instigate a moral panic ahead of August's Olympic Games.

A city apartment dweller who goes by the moniker Rio de Nojeira - loosely translated as River of Filth - has regularly filmed people getting accosted by thieves on main thoroughfares. Passers-by selectively ignore the incidents.

The attempted - and sometimes successful - muggings look to target items like phones, jewellery and easily-accessed shoulder bags.

The thieves work as a gang. When the persecuted fend off an assailant, they are often targetted by others from behind. Traffic regularly whizzes by during the ordeals.

The concern is that New Zealanders travelling to support Games athletes might be subject to such circumstances.

New Zealand Olympic Committee secretary-general Kereyn Smith recommends caution.

"Most of those people going to Rio are aware they have to be incredibly careful. We're sharing information to anyone in the belief it will help them make sensible decisions.

"People need to be vigilant and take appropriate measures, like not wearing flashy jewellery or wandering about showing off phones and shoulder bags.

"At Games time, we expect a different environment because 60,000 extra military personnel will be deployed in Rio, all of whom, as I understand it, have the capacity to work as members of the police force.

"Issues of security and safety always tend to come under the spotlight in the lead up to a Games, but you can't be too careful applying a respectful approach in and out of the [Olympic] bubble."

The safetravel.govt.nz website advises Kiwi travellers to Brazil to "exercise caution due to violent crime". Visitors are advised to register their details with the site in case of emergency, and to be mindful of their personal security because "petty theft is a major problem".

Other advice includes:

- avoid wearing or displaying items that appear valuable such as jewellery or mobile devices.
- bags should be kept closed and carried close to the body.
- no resistance should be given if you are the victim of an armed robbery or mugging as this could lead to an escalation in violence.
- avoid visiting isolated areas.
- beware fraudulent ticket sellers and only purchase from authorised sellers. The on-selling of tickets is a criminal offence.

On the plus side, New Zealand passport holders arriving in Brazil between June 1 and September 18 will be exempt from a visa for stays of up to 90 days, provided their passports are valid for at least six months after the date of departure.