A woman's body has been found in the rubble of a collapsed townhouse in Whalan, Sydney.

The deceased woman, in her 30s, was discovered despite hopes of finding her alive.

Earlier, two women and a small dog were rescued from the site.

Five others injured in the explosion have been discharged from the hospital.

Search teams faced significant challenges, including a gas leak and fire beneath the debris.

The cause of the explosion remains unknown and is under investigation by NSW police.

International urban rescue teams are aiding in the ongoing search efforts.