Authorities have accused a 19-year-old of igniting a fire by tossing a firecracker into dry grasslands along Temby Avenue in Kalamunda, located in the Perth Hills roughly 25 kilometers from the city center, around 12:20 a.m.

The firecracker reportedly set off a bushfire that escalated rapidly.

Efforts to control the blaze involved the deployment of a waterbombing helicopter and several firefighting teams, yet the flames continued to rage well into the morning hours.

By 8:30 a.m., an emergency alert was issued, advising residents in areas including Maida Vale, Forrestfield, and Kalamunda to evacuate immediately as the fire expanded over 25 hectares.

Warnings were issued to residents about imminent threats to their lives and homes.

The warning was downgraded to a Watch and Act just before 12.30pm.

Fire activity has decreased, but it still poses a danger to lives and homes in certain areas due to changing conditions, DFES warned.

Residents in parts of Maida Vale, Kalamunda, Forrestfield and Lesmurdie are urged to stay alert and monitor their surroundings for changing conditions.

That includes people in the area bound by Norwood Road, Taylor Road, Colac Place, Bird Road, Alpine Road, Wandoo Road, Holmes Road, Lewis Road and Anderson Road.

Locals bound by Hawtin Road, Norwood Road, Welshpool Road East, Lesmurdie Road, Kalamunda Road and Canning Road should also be vigilant.

Doors and windows should be closed to keep smoke out and residents should look out for spot fires on their properties.

Residents in parts of Forrestfield and Maida Vale, namely those bound by the Roe Highway, Quenington Court, Hawtin Road and Hartfield Road are no longer threatened by the fire.

The bushfire is currently moving slowly in a westerly direction. It is contained but not controlled.

An evacuation centre has been set up at the High Wycombe Community and Recreation Centre, 200 Newburn Road, High Wycombe.

A community meeting will be held there at 1pm today.

Several roads in the area have been closed, including Temby Road, Holmes Road at Wandoo Road, Norwood Road at Holmes Road and Hawkin Road at Maud Road.

More than 2000 homes lost power overnight as a result of the blaze.

Power was restored to almost all impacted properties by 9am, according to Western Power.

The 19-year-old man, from Kalamunda has been charged with a breach of duty (of care).

He is expected to appear before Perth Magistrates Court today.