A 12-year-year old boy has pleaded guilty to lighting two bushfires at Port Stephens last year, at a time when massive firestorms were sweeping across the state.

The boy, who was 11 at the time of the incidents, has admitted using a cigarette lighter to start a blaze at Raymond Terrace and another at nearby Heatherbrae that destroyed thousands of hectares of land on October 13 last year.

The bushfires were among dozens of fires that devastated large areas of New South Wales.

Both bushfires lead to emergency evacuations in affected suburbs and the closure of the Newcastle Airport at Williamtown.

The 12-year-old was due to face Broadmeadow Children’s Court today, but the case has been moved to July after the boy pleaded guilty to two counts of intentionally and recklessly causing fire.

His bail has been continued.

The court was previously told the fire at Raymond Terrace started when an abandoned mattress was set alight, while grass was set alight at Heatherbrae.

The boy was accused of using a tree branch to fan the flames at Heatherbrae.

Last month charges against an alleged 15-year-old accomplice were dismissed under the Mental Health Act.