Police are treating a fire at a University of Canberra student accommodation block as suspicious.

They are seeking witnesses to the fire at the university on Sunday evening.

"Around 9.10pm, police attended the student accommodation unit, where ACT Fire and Rescue had extinguished a couch which had been set alight. Police are treating the fire as suspicious," they said in a statement.

Earlier, the Emergency Services Agency said authorities had been alerted when a passer-by noticed smoke and flames coming from the Cooinda Street building about 8.46pm.

Firefighters arrived to find the building vacant and heavily smoke logged with all four stove stop elements in the common kitchen area turned on. The block of six units sustained smoke and heat damage. 

Police ask anyone who saw any suspicious activity near the  University of Canberra residences or Arscott House between 8.30pm and 8.50pm to contact Crime Stoppers on 1800 333 000 or at  www.act.crimestoppers.com.au. Information can be provided anonymously.

It was one of several incidents that kept emergency services busy on Sunday night, including a house fire in Watson. Police are investigating after a 65-year-old man was found dead after the fire.