Suspected arson attack at Sydney Salvos

A fire that ripped through a Salvation Army centre in southwest Sydney was deliberately lit, say police.

Emergency services were called to the corner of Bathurst Street and Memorial Avenue, Liverpool, about 6.15am (AEST) on Sunday after a trolley full of rubbish was set alight at the back of the building.

The fire then spread into the building itself.

NSW Fire & Rescue said the blaze was extinguished later on Sunday morning but 50 per cent of the building had been damaged.

A crime scene has been established and investigators are waiting for the scene to be declared safe before forensic examinations can begin.

The intersection remains closed and police are appealing for anyone with information to call Crime Stoppers on 1800 333 000.