As New South Wales continues to battle the bushfire disaster, it is being reported that two boys, aged 11 and 14, have been charged with starting two separate fires - one near Newcastle and another one at the Hunter Valley. In a similar incident, two teenage girls, aged 12 and 13 have also been arrested on charges of deliberately lighting grass fire.

Media reports quoting police sources said the boys started small grassfires on Oct 13, one at Raymond Terrace and the second later that day at Hertherbrae.

The childish act of stupidity ended up destroying a number of sheds and burned more than 5,000 hectares of bushland in the vicinity. The fire the boys started burned very close to Newcastle Airport at Williamtown, forcing it to shut operations on Thursday. The billowing black smock could be seen the Newcastle CBD, reports said.

Investigations by authorities revealed both fires were deliberately lit by the boys.

On Monday morning, officers arrested one of the boys, the 11-year-old, from his home in Raymond Terrace. After questioning him, the boy was charged with two counts of intentionally causing a fire.

He will appear in children's court later on Monday.

The second arrest happened after public raised the alarm on seeing the teenage boy running away from the fire which was spotted near a tennis club on the New England Highway on Sunday.

Reports said the fire burned through 200 square meters of vegetation, including more than 20 trees in the vicinity and a section of the club's fencing.

The 14-year-old was arrested from his house and charged for the crime. Reports say he was refused bail and was due to appear in the Children's Court on Monday.

''It's one thing to be an adult criminal in setting fire,'' Rural Fire Service Commissioner Shane Fitzsimmons was quoted as saying in The Australian.

''It's another thing, and it saddens me, that young people could actually not see the consequences of this sort of reckless behaviour and I'm pleased that, with the support of the community, police have actually even able to make an arrest and deal with someone in lighting these fires,'' Mr Fitzsimmons added.

The Australian reports that on Sunday, in similar acts, two teenage girls, aged 12 and 13, had also been arrested on charges of deliberately lighting grass fire.

The newspaper quoted Police Minister Michael Gallacher, calling it an "act of stupidity" to light fires under the present dangerous conditions.

''You're putting people's lives at risk potentially, you could well be even putting your own life at risk if you were to set fire to bushland and find yourself stuck in the middle of it,'' he said.

''It's a serious criminal offence and it will be dealt with seriously,'' he further said.