Amnesty International is stepping in to make sure the human rights of protesters in south Auckland are respected.
Police and protesters have spent a peaceful night at the Ihumātao site, which has been earmarked for a housing development which local iwi oppose. Police made three arrests yesterday.
Amnesty executive director Meg de Ronde says it is the first time in a number of years independent human rights observers have been sent to an event in New Zealand.
"We do think it's an important moment in New Zealand, and clearly it is something a lot of people are interested in. We just want to make sure things go smoothly, and there are people there who are monitoring what's going on."
- Passions boil over as Ihumātao protest continues overnight
- Jacinda Ardern's refusal to intervene at Ihumātao a 'cop-out'
Police said a "small number of people have acted in a reckless and dangerous manner".
"Police continue to urge demonstrators to behave responsibly, respect the police cordon and act in a peaceful manner," the force said in a statement.
"This is a challenging and complex situation involving a long-running dispute between the parties involved."
De Ronde says they are confident police and protesters want to remain peaceful.
"But occasionally when you get large groups of people coming together... there can be escalations that are unintended."
Ihumātao, tucked between Manukau Harbour and Auckland Airport, is Auckland's oldest settlement and regarded as sacred by local Māori. In 2013 Auckland Council rezoned it so that Fletcher Building could build a 480-house subdivision.
A historian told Newshub it won't be the last site Māori occupy if consultation does not improve.
Archaeologist-historian David Veart says a lack of effective consultation and leadership has led to the situation becoming a mess.
"It's my opinion as an archaeologist who's worked in the field for the last 30 years that this sort of problem will grow unless we cast our net wider in terms of who we consult with."
Veart is also concerned about archeological assessment of land for future housing developments, calling the Ihumātao situation a "complete bloody mess".
"It's a bit like building houses next to Stonehenge. When you've got as important archaeological site, you have to consider it in a broader context."