TELSTRA technicians are working around the clock to restore full mobile coverage to customers in Victoria's west and southwest.

Approximately 65 per cent of 60-thousand affected customers had their mobile phones back up and running by 6pm last night after a fire severely damaged the Telstra Exchange in Warrnambool early yesterday.

But Telstra says it will be a number of days before landlines and home internet connections are re-connected.

Telstra says mobile phones voice calls are the top priority for the 30 technicians assigned to the job.