Three teenage girls have been arrested for arson over 13 grassfires police allege were deliberately lit on the New South Wales mid-north coast.

The girls, aged 12, 13 and 14, were arrested in South Kempsey on Wednesday by officers from Strike Force Tronto, which was set up to investigate the fires.

No-one was hurt in the blazes, which damaged grassland before being controlled by rural firefighters.

The teens will be dealt with under the Young Offenders Act.

The night before the arrests more than 60 people held a meeting to discuss recent fires with authorities.

At least three homes were under threat at the Turner's Flat fire west of Kempsey. ( ABC Mid North Coast: Luisa Rubbo )

Rural Fire Service (RFS) spokesperson Greg Allan said there was zero tolerance for arson.

"It's a criminal act and basically it puts the lives of the public and firefighters at pretty grave risk.

"We say to anyone who's stupid enough to deliberately light a fire that they should know they will be caught … and they will be brought before the courts," he said.

Superintendent Lachlan Ison, RFS zone manager for Kempsey and Nambucca, said it was disappointing that three youths had allegedly started the fires.

"Any sort of fires in the Kempsey area is very disappointing but when youths as young as that have been identified, it's extra disappointing."

'Not just Kempsey'

Mr Ison said Kempsey had experienced a spate of fires in the past three months and that a number of areas around the state might face problems in the ongoing dry conditions.

This week the arson squad targeted the mid-north coast town.

In response to information from the local community, officers arrested the three girls in relation to the alleged arson offences.

"To actually get that affirmative action and a bit of feedback from the local community in that regard has been pretty positive," Mr Ison said.

The Turners Flat fire was at Watch and Act level a week ago. ( ABC Mid North Coast: Luisa Rubbo )

"It is an acknowledgement that it is a bit of problem particularly in the Kempsey area and to have the community on board to help in that regard is a positive," he said.

Mr Ison said the arson squad was targeting fires in and near the town.

"As the locals know, in close proximity to Kempsey there are large areas of grassland and they are of particular concern because of their proximity to houses but also for the potential for grasses to burn very quickly with wind-driven fires."

Tougher penalties for arson

Firefighters have welcomed moves to increase the time convicted arsonists will spend in jail.

The NSW Government announced this week it would extend the non-parole period for the offences from five to nine years.

"The increase in the penalties is positive … it is acknowledging that this type of behaviour is unacceptable in our communities," Mr Ison said.

"Particularly with the ongoing dry conditions, the last thing we need is any more either illegal or careless fires.

"We've got a lot of fire season potentially ahead of us and we need to stay on top of it in terms of being able to address or attend the fires that do occur."

A bushfire near Crescent Head east of Kempsey went to emergency level after threatening a number of properties. ( ABC Mid North Coast: Luisa Rubbo )

Fires were not good for the local community nor local firefighters, whether they be Fire and Rescue or volunteers, Mr Ison said.

"They've got better things to be doing with their family in their spare time and the threat from these fires has been demonstrated in the past. We need to jump on it the best we can."

More arrests expected

Mr Ison said the taskforce gave the community a commitment that it was here for the longer-term after concerns were expressed at the public forum that it would be departing.

"It's not just a one-off issue for Kempsey. It needs to be a cultural change and one of education," he said.

The police district commander, Superintendent Paul Fehon, said officers would continue to proactively target suspects and investigate all deliberately lit fires with the goal of significantly reducing fires on the mid-north coast.

Firefighters west of Kempsey experienced challenging conditions with strong westerly winds fanning blazes. ( ABC Mid North Coast: Luisa Rubbo )

"Deliberately lit fires not only put a strain on emergency services, but can also be life-threatening if they get out of hand," he said.

"I urge the community to help us stop these fires and anyone with information about suspicious activity is asked to contact police."

Investigations into other arson offences are continuing and police expect to make further arrests.