Mount Maunganui has been upgraded to the highest alert level after three new landslides within 48 hours.

They come six months after a big landslide fell on to Mount Maunganui Holiday Park, killing six people.

Tauranga City Council recovery manager Charlie Rahiri said the alert had been lifted to Level 3, leading to the closing of Adams Avenue at the base of the mountain between Pilot Bay and the Maunganui Road roundabout.

There had been "a major regression" at the site of the original landslide, extending 20 metres with a runout of 100 metres, he said.

The latest landslide had not extended as far as the original runout but the material was "saturated, mobile and fluid", he said.

The council said in a statement that geotechnical engineers were assessing the site, with the closure expected to remain in place until at least Monday.

Residents and businesses could still access Adams Avenue via the southern footpath.

"The closure is a precautionary measure following slips on Mauao overnight, to ensure public safety while the area is at higher risk of further movement."

Six people died in January when a large landslide fell onto the campground below.

The council said Māori Wardens were managing the current closure until temporary fencing was installed later on Sunday.

Motorists and pedestrians have been asked to avoid the area and follow any signage or directions from staff on site.