Firebombs found in hunt for arsonists

Australian Police have discovered the remains of what may have been two homemade bombs used by arsonists to set tinder-dry forests on fire.

New South Wales state Premier Bob Carr has vowed to punish those who started the fires.

At least half of the wildfires have been deliberately lit since the crisis started on Christmas Eve and police have arrested 21 suspects.

These include 14 juveniles, aged between 9 and 16 years.

"I want to rub their noses in the ashes they have caused," a Premier Carr said.

While adult offenders would face prison terms of up to 14 years, minors would be made to confront burns victims and families who lost homes.

They would also work on rehabilitation projects for scorched forests.

As the hunt for more arsonists continue, police say they found the pieces of what appeared to be incendiary devices at two separate charred bush-land sites, including one where fierce flames threatened hundreds of homes, just 11 miles from Sydney.

Senior deputy Police Commissioner Ken Moroney said the device found there was "capable of being ignited and causing substantial damage".

He declined to give more details, saying police feared copycat attacks.

Some residents had reported hearing an explosion just before the fire broke out and triggered two days of havoc across Sydney's affluent northern suburbs.