Two homemade explosive devices were detonated outside a Hamilton shopping centre this morning - in an apparent effort to crack open an ATM.

Police teams search through an area near the Chartwell Mall in Hamilton after reports of possible homemade explosives on 6 August, 2020.

Police teams search through an area near the Chartwell Mall in Hamilton after reports of possible homemade explosives on 6 August, 2020. Photo: RNZ / Andrew McRae

Police earlier said what appeared to be homemade explosives were found at the Chartwell shopping centre.

Roads around the mall - Lynden Court and part of Comries Road - were cordoned off this morning about 8am, but have now reopened. The centre remains shut to the public.

A robotic machine operated by police was for a short time deployed from a van but was put back about two hours later.

Police said the explosives appeared to target an ATM located on the exterior wall of the shopping centre at its southern end.

Initial indications suggest two devices had already detonated before police were notified, with damage contained to the ATM and immediate surrounds, police said. No-one appeared to be injured in the incident.

The main operation at the mall has now wound down with police now focusing their attention on a car park at the southern end of the complex.

Six officers are searching a small area of the carpark.

Police said Specialist Search Group was searching the shopping centre and surrounds to ensure nothing of concern was left unattended and there was no further risk.

The Defence Force explosive ordnance disposal team was also at the scene.

Police teams search through an area near the Chartwell Mall in Hamilton after reports of possible homemade explosives on 6 August, 2020.

Police teams search through an area near the Chartwell Mall in Hamilton after reports of possible homemade explosives on 6 August, 2020. Photo: RNZ / Andrew McRae

Hamilton City Council said the Chartwell Library was also shut while police responded to the incident.

A Hamilton couple, who live opposite the centre, say they were woken by a loud bang early this morning and then saw two black-clad figures running through the mall's carpark.

Yolanda Julius said she and her husband, Peter, were woken at about 3.45am.

"That bang was so loud, you know, we were still sleeping ... jumping out of the bed, looking through the window and just saw two guys running through the carpark. They had like black clothes on."

She said their faces appeared to be covered.

Police teams at the Chartwell Mall in Hamilton after reports of possible homemade explosives on 6 August, 2020.

Police teams at the Chartwell Mall in Hamilton after reports of possible homemade explosives on 6 August, 2020. Photo: Supplied / Yolanda and Peter Julius

Peter Julius thought it might have been a car crash.

"We heard this loud bang or explosion or something like that. We ran towards the window but we could see nothing," he said.

"Then two guys were running from the ANZ ATM towards Hukanui Rd. It was just quiet after that."

They didn't contact police at the time but have spoken to officers this morning.

Kevin Dornauf also lives across from the mall.

"I got straight up, just put some slippers on and went straight outside to see what had happened and didn't really see anything," he said.

"By the sound of it, it was a bomb. Not that I'm an expert on bombs or anything but that's just what it sounded like - just a very loud bang."

He saw "a little bit of a haze" near the carpark area, which at the time he thought was just fog.

Police teams cordoned off the area near Chartwell Mall in Hamilton after reports of possible homemade explosives on 6 August, 2020.

Police teams cordoned off the area near Chartwell Mall in Hamilton after reports of possible homemade explosives on 6 August, 2020. Photo: RNZ / Dan Cook

RNZ reporter Andrew McRae told Morning Report police were moving the public about another 100m away from the mall about 8.30am.

He said the carpark in the mall appeared to be empty as the mall doesn't open until about 9am, but the Countdown supermarket attached was still busy up until about 8am when they were evacuated.

One person exiting the mall told McRae that they were not told what was happening but it appeared the devices were inside the mall.

Police teams search through the area near the Chartwell Mall in Hamilton after reports of possible homemade explosives on 6 August, 2020.

Police teams search through the area near the Chartwell Mall in Hamilton after reports of possible homemade explosives on 6 August, 2020. Photo: RNZ / Dan Cook

Hukanui Primary School earlier posted on its Facebook page that the closure of streets may affect parents dropping off their children this morning.

"Police have informed us that this has no impact on us here at Hukanui School."

Chartwell Shopping Centre was formerly owned by Westfield and is now owned by Diversified NZ Property Trust.

In a statement, Stride Property said the centre has been evacuated as police respond to the situation and they are co-operating with police.

"Chartwell Shopping Centre treats the safety of its retailers, customers and the public as the upmost priority and will await further notice from the police regarding reopening the centre."