An ACT Policing spokeswoman said it was too early in the investigation to link the two fires together.

They are calling for witnesses to the fire at Brierly's Cafe in Weston Creek.

The cafe was cordoned off with police tape on Thursday morning and a police officer stood guard outside.

A door at the back of the building was broken in and revealed some of the damage inside.

Police said offenders broke into the Brierly Street cafe between midnight and 12.30am, activating the alarm and alerting the owner.

A security firm contacted the owners, and on arrival, found the kitchen alight.

Police were called to the fire at 12.47am, and firefighters were already on the scene extinguishing it.

The fire was contained to the cafe, and did not spread to neighbouring businesses.

Workers from a nearby business said the cafe had been closed for several months.

The fire was deemed as suspicious, and investigations were handed over to ACT Policing at 2.30am.

In mid-January 2012, fire destroyed the kitchen at the then AD's cafe, causing $100,000 in damage.

The ACT Policing spokeswoman said officers had investigated the mid-January 2012 suspicious fire for seven months, but had eventually closed the investigation because they had not identified a motive or a suspect.

She said there had been no witnesses to the 2012 fire and no person or vehicle identified on CCTV.

Police are asking anyone with information on the fire or who may have spotted anyone acting suspiciously in the area to contact Crime Stoppers on 1800 333 000.